Installing the Door Handle Lights : Issues

I am installing blue door handle lights on the fit. Basically they are a little strip of LEDs which must then be wired through the door and into the battery. However, I want mine to come on when the car unlocks, so we have to find out which circuit the dome (overhead) light is on, and wire it into that. It's gunna take some work. Especially since I don't know how to remove the door panels on the Fit yet. When I figure out how to do it I will take pictures every step of the way - that way you guys can do it too!