I installed the illuminated sills. d cleve is correct, if you have the LED undercarriage lighting you will already have the accessory connectors on both sides. The instructions were fairly clear and no real hiccups. You will need to contort yourself a bit to get to the connectors but nothing outrageous. Also, note that the passenger side does wire up slightly different as the harness has a wire that crosses the car connecting both harnesses.
I did invest in some posi-taps, never used them before but look sturdier than the ole butt splice.