I bought an acrylic guitar the other week. It was on ebay for cheap and it looked quite beautiful, and I already have an acrylic bass so I bought it, despite knowing that these instruments are of somewhat dubious tonal quality (even though the auctioneer gave assurances that it sounded ALMOST as good as a decent Epiphone Les Paul). I was already planning to "do" something to it, when it arrived and proved to sound not unlike a ukelele squeezed through a baked bean tin microphone, I was decided. I henceforth procured some nice colour changing rainbow LEDs, and stealthily gathered my soldering equipment.
Basically, there are two sections to the process as I did it. I will outline these separately because they are essentially two projects stuck together. The first section involved the mount and wiring of LEDs and pretty much anyone can do it. The second section, fabricating and wiring a guitar effect board is quite advanced by itself not to mention installing it into a tiny guitar control cavity, I would only advise undertaking this if you already know a bit about effects, electronics, or are REALLY determined to learn.
You know the rest- I am not responsible, ever, for anything, blah blah blah so ner.