I always dreamed of building a guitar but didn't know where to start. One day I came across the Fender acoustasonic and I loved the Idea (but not the look). so I bought a used Epiphone les paul special ii and decided to turn it into a Gibsosonic guitar. I had fun and it sounds great.

the nice thing is that this could be done with any guitar body.

Supplies

Used electric guitar
Acoustic guitar bridge
Pieso pickup
5mm top wood (I used a bookmatched Engelmann Spruce)
China-made brace wood kit for acoustic guitar
Titebond 2 premium wood glue
Double-sided carpet tape
Wood stain
Wood finish
Jigsaw
Router (can use a trim router, I had a plunge router)
Clamps, lots and lots of clamps

Step 1: Take Apart the Guitar

First, I needed to strip the guitar to its bare bones.

that includes:

removing the strings.
removing the machine heads from the headstock (optional, but I changed the headstock as well)
removing all the electronics (knobs, pickups, switch, bridge, volume and tone pots)

at this point, you can also sand the body to remove any existing paint/stain/finish from the bottom and sides.

Step 2: Route the Body Cavity

I printed a template and marked it on the guitar body. then I free-handed routed the cavity. that did not work as planned.

lessons learned:

make many shallow passes (1/4 inch at a time max) with the router and don't try to plunge in and remove all the material in one go.
if possible, make a wood/plywood/mdf template, and use a template bit in the router. my attempt of free-handing the route ended up with ugly uneven sides. so I flattened it and glued the top on the body instead in the body as I intended.
use protection. ears, eyes, and a mask.
clamp the body well.

Step 3: Prepare the Top

with the router, I cut a 3" sound hole and the hole for the pickup.

then I measured and cut the braces (which were too long) and placed them where I found fit, no methodology here. I also took a piece of scrap wood and glued it as a plate under the bridge.

the last thing I added (not in the pictures) is 2 layers of 3/4" plywood with the same sized hole as the sound hole. This gives more structure and depth to the hole. Then I used a 1/4" round over from the top side of the hole to blend this plywood in.

glue everything and let it dry.

lessons learned:

when gluing the braces take into account the rim of the body that the top should sit on.
pickup holes are much easier to cut if you 3d print a template (example)
the sound hole is much easier to cut with a hole saw.
it's easier to put the piezo pickup before gluing the top.

Step 4: Glue Up Trim and Finish

Nothing much to say here. align the top and body, and use plenty of glue.

after the glue is dry, use a flush trim bit to trim the access top and round it over.

sand the top and body to 320 grit, then stain and apply the finish (I also sanded the neck and applied the same black stain).

after that, I connected all the electronics (the piezo pickup goes behind the bridge) and reattached the neck.

lessons learned:

because I was using a ready-made body, the hole for the cable connector was already made. I missed it and when I ran my flush trim bit it plunged into the hole and made a "dent" in the top. I had to redo the top. Don't be me, pay attention.
Don't forget to gound the bridge!!!!

Step 5: Optional, Carve the Headstock

I 3d printed a template for what I wanted the headstock to look like. then I traced it onto the headstock.

With a combination of a drill, a coping saw, and many rasps, I cut and sanded the headstock

Step 6: Conclusions

This is my first ever project of this kind. if I can do it, anyone can.
youTube is an infinite source of knowledge.
Overall project cost (without tools cost) - ~200CAD (~150usd) including the guitar/wood/bridge
Now it's time to learn how to play guitar