These are general instructions for rewiring an old fencing foil.
If you wish to wire a new, bare blade, please start with step 2, as the step before that is just for stripping/preparing a used blade.
I do assume you have basic knowledge of terms and names of items here. If you don't know what I'm talking about at all, you shouldn't be (re)wring a blade in the first place.
But there are variations in fencing weapons, so if you come across a hitch, do feel free to ask.

If you have an electric epee you wish to (re)wire, the steps for that will be very similar to the ones presented here. It is almost impossible for me to create a second instructable for rewiring an epee, but once I have the time, I may add some epee pointers into this instructable.

If you have an electric saber/sabre: Take your blade, stick your bell-guard, socket, bell-pad, grip and pommel on (in that order). Remove any insulation from the socket. You're done.

Please read through all the steps before you start rewiring! Some of these steps are highly time sensitive (i.e. the gluing), so make sure there aren't any surprises once you start.

Disclaimer: if you muck up your weapon, it's not my fault. The directions I present here are reasonably safe/not likely to damage anything if followed correctly.

Items needed:
Foil blade
Point assembly: Barrel, tip, spring, 2 screws, wire+cap
Spaghetti/wire cover tubing
Tension-provider rig (See step 4)
Bell-guard
Socket
Bell-pad
Grip
Pommel (nut)
Tip tape

Tools needed:
Glue (Emblem adhesive is the most accessible, but superglue, Zap-a-Gap, and others may work too)
Point setter (or anything suitably blunt that will fit all the way to the bottom of the point barrel)
Small screw driver
Screw driver/Hex wrench/wrench/narrow tool shaft (for tightening pommel/pommel nut)
Solvent pipe (Optional, but is really helpful. See step 1)
Various chisel-like items (I used a fine point awl, dentist's pick and small screwdrivers)
Hammer (if your chiseling needs a bit of brute force)
Solvent (I usually use acetone, but kerosene-like stuff works too)
Rags (To aid clean up)

Yes, I am pretty verbose, but that also means I probably address most questions that may arise within the text. Read carefully before you ask questions that I've already answered--I might not call you an idiot, but I'll be thinking it.

Addendum: I realize my photo-documentation is not as complete as I would like it to be. I am, however, no longer on the same continent as my weapons/wiring equipment and cannot take additional photos. I am sorry. I can try to supplement with more detailed description, but please do not make photo requests.

Step 1: Strip the Blade Bare!

Remove the point, pommel, grip, pad, socket, and guard.

Remove the wire from the groove down the length of the blade:
- If you do not have a solvent pipe*:
Wear eye protection. Find one end of the wire (I advise starting with the tang-end), drip some solvent on the area and along the groove in the immediate vicinity. Wedge a pointy-ish object and start chiseling. Work on sections of 1-3 inches at a time--most solvents will evaporate too fast for you to tackle larger sections. Drip, chisel, pry, curse, yank. Repeat. A hammer may come in handy.
-If you have a solvent pipe*:
Fill your pipe to the height of your blade's groove, insert blade and let soak for ~10 minutes. Remove blade, pick one end of the wire from the groove, grab with pliers or wedge a pointy object under the wire and gently pull strip wire away from blade.
I have managed to remove every wire in a single piece when using my acetone pipe--it is exceedingly effective.

Scrape the blade to remove excess glue residue. Wipe with a rag. Etc.

*Make a solvent pipe!
Purchase a ~3 foot section of 1" (or so) copper pipe, and a matching end cap (preferably with solder pre-applied) Cap pipe, solder. (I just went over the end with a little blowtorch for a minute or so.) Cool, and then check for leaks by filling with water. If there are no leaks, then you've got yourself a solvent pipe!
If you're desperate, you can use PVC piping as a temporary, disposable solvent pipe. A matching end cap will fit tightly enough without any glue, but most solvents will dissolve the PVC pretty quickly. Do not use for more than 30 minutes!

Step 2: Begin Assembling the Point

Gather your point components. At the moment, you will only need the barrel, and wire. The rest of the components will be added once the wire has been glued down and set.

Grab the barrel, thread the wire through so that it sticks out the narrow end of the barrel, with the cap sticking out towards the wider end. Pull the wire through till the cap is an inch or so from the barrel, and screw the barrel on to the point of the blade. Make sure the wire is in the blade groove, can move freely, and does not get caught in the blade/barrel threads.

Use your point setter (or suitably blunt and narrow object) to push the cap into the bottom of the barrel, slowly. Apply a little tension on the wire, "pulling" it through. You're not actually using the pulling pressure to set the cap, that's just to make sure the wire isn't getting caught and crimped within the barrel. Assuming the wire is freely movable through the barrel and groove, you probably don't have to worry about it getting crimped. Just don't yank the wire out from the cap!

If you want to, you can assemble the rest of the point and test the circuit now, just to make sure the cap-wire connection hasn't broken during your installation. I totally don't remember which pin leads to which socket, so ... you're on your own here. Pretend to link the wire to the socket, plug stuff in and poke something. That's about all I can tell you here. (& make sure you disassemble the rest of the point before proceeding.)

Step 3: Spaghetti

Thread a section of spaghetti (3-5" is good) over the non-cap end, and slide it up so that it will rest approximately where the blade groove ends, right at the junction of the blade forte and the tang. I generally use a bit of masking tape to secure the spaghetti at this spot, while allowing the wire to slide as needed.

Step 4: Glue!

No real photos of the gluing. I was using Zap-a-Gap and had absolutely no time to photograph what I was doing. The idea is simple enough that I hope text alone is sufficient to convey the directions. I can't imagine what a photograph might tell you that text cannot...

Anyhow.
Start from the point-end of the blade and glue your wire down. Work quickly--you need to get to the other end of the blade before the glue has set at the beginning!

With emblem adhesive, you can try dripping some glue on to your fingers and quickly coating the length of the wire and then popping it into the groove and then applying a bit more. You may also just apply as you go, holding the wire into the groove and applying the glue over it. In either case, you may wish to drag a pointy-ish item over the wire to press it down (without damaging the insulation on the wire). Once you have the wire glued down (and before the glue has dried), slide your tension-rig thing* on to the tang, and flex the blade (with the wire/groove on the outside), clipping the rig into the barrel to hold the flex. Allow to dry the recommended time (see the glue for drying times).

With Zap-a-Gap (and other superglue-like adhesives), you just have to work very quickly! Unless you have ultra-slow drying superglue, you may wish to reverse the steps a bit, and start with flexing the blade with your rig* and then gluing the wire down.

What's with the flexing and bending? If you simply glued the wire down and let it dry without any flex in the blade, even moderate bending of the blade during use will snap the wire. By giving it the flex before it dries, that provides some elasticity/give/tolerance to the wire.

*Build yourself a tension-rig, blade-flex-holding-doohickey, thingamabob:
Get a lanyard clip, large crab-claw clip, or some other key-chain related clip that will fit into the barrel of your point, and a split-ring, clip, lock, etc that will slide on the tang of your blade, but will stop at the forte. Now attach the two with a length of lanyard, chain, rope, etc such that the blade is flexed to approx. 45 degrees.

Step 5: Final Assembly

You can start with the point-end or grip-end. I am usually confident that my assembly isn't broken anywhere, so I start with the grip end, so that when I do my final testing, I have the socket already secured. If you want to make sure you didn't mess anything up, you may start with the point assembly.

Grip assembly:
Slide your bell-guard over both wire and tang, aligning any notch in the slot to the wire.
Slide your socket over wire and tang, once again paying attention to any notches.
Put the bell-pad on just the tang, leaving the wire trapped under the pad.
Slide grip on the tang, align any notch with where the wire is under the pad, and secure with pommel.
On your socket is one insulated pin-hole, and one uninsulated one. Your wire will be attached to the insulated one. Strip away some insulation on the wire (it's probably cloth insulation, so just unwrap an inch or two of the wire, and trim away the extra threads.) Figure out what you wish to do with the excess wire. I frequently wedge some under the bell-pad, and then wrap it around the socket arm once or twice. Now loosen the pin-hole, wrap the wire around the exposed shank, and tighten again, making sure it is fully insulated from the rest of the socket.

Point assembly:
Insert spring into barrel.
Align the screw holes on the tip to the screw holes on the barrel, and insert tip, pressing until the holes align from barrel to tip.
Screw in screws.
(Hints: use a magnetic screw driver, and don't worry if the screw holes aren't 100.000% lined up--if there's a tiny (but I do mean tiny) bit of misalignment, it'll fix itself when you insert the screw. And once you get one in, you don't need to be holding the tip down to get the other in. Also! Don't let go of the tip--the spring will probably shoot it out and you'll have a difficult time finding it again!)

Now plug in your body cord and buzz-box and see how you did!
You may wish to do some preliminary weight testing, too. If you don't have a weight on hand, know that the full weight of a foil is pretty equal to the weight you'd be testing with, so flip the foil so that it's point down on the floor, press it down and see if the spring will push the weight of the foil back up.

Final flourish: Tip tape!
Tear off 6" of tip tape, stick it on the blade, lengthwise, starting just below the barrel-screw holes. Wrap the width of the tape around the blade firmly. Tear off another 1.5" or so of tape, and tape widthwise around the barrel, lining up the edge as close to the edge of the barrel as possible, without sticking over. Make sure no bare metal is exposed from the tip down for the length of the tip tape. This taping method allows you to detach the tip while removing only the small bit of tape, rather than trying to strip down part of the 6" tape as well.