i haven't done one myself, but I'm comfortable putting in gauges, afc/avc-r, putting in a standlone ecu etc, and i didn't want to touch my remote start:)
Then again, i'm sure it is easier than we think. I'd suggest trying to find some install diagrams to see what they look like. I paid quite a bit in having mine installed (compustar) but i know it is done right and I have a lifetime warranty on everything. That alone lead me to have it installed from a shop.
However, if you do end up trying this out, let me know. I'd be interested in helping out.
Keith