All I did with my 4 pin was disconnect from the plug on the frame along with the ground wire, disconnect the taillight plug and some x-mas tree clip if I remember and out she came. The new 4/7 went in just as easy, literally plug and play. There shouldn't be that long of harness to go from the bumper to the frame, maybe 1-1.5 ft and the one to the taillight was less by half maybe. Sounds like one stop shopping will take care of everything you need so a half hour installing these things and you're good to go.
