What you'll need...
A donor electric guitar
If adding a second pickup...
(I've always been a fan of musicians that run 2 amps to their guitar ala Bob Log III)
A piezo buzzer
A 1/4 inch female mono jack
1 volume knob
all the above can be had at your local Radio Shack
And other things you'll need...
Soldering iron and solder
some extra wire length (I used an old headphone wire)
A drill with various drill bits
and a means for cutting wood
Everything else will be supplied by the donor guitar.
Step 1: Break 'em On Down...
Start by removing the strings.
After that the neck will unscrew from the body.
Then you can unscrew the bridge and pickup.
You will have to cut the wires from the pickup and give yourself room on the pickup wiring. You will be soldering them back together.
Unscrew the pick guard and the cover on the back.
The volume and tone knobs can be pried up and off.
You then can unscrew the bolts holding the potentiometers and the mono jack.
And don't forget the jack plate and screws.
Keep all the wiring intact with the exception of the wires you cut to get the pickup out. Set aside everything you take off the donor guitar as you will need them.
At this point you should have something like the picture. Now would be a good time to remove the hinges from your jewelery box as well.