The kit has some split adapters to tap the brake lights and blinkers without cutting any wires, but you can do the same thing manually with typical auto-splice connectors. The kit also comes with a power booster to make the trailer lights brighter, but I didn't use it on mine because I found just buying LED light-bulbs for the trailer and replacing the incandescent bulbs worked just as well without putting a big power load on the rear lights themselves. You basically have to take the rear trunk floor apart and the side plastic panels to get to those wires on each side for the tail-lights.
I don't have the old wiring diagram that came with my kit, but you only need a common ground to the frame, one wire from the left and right blinkers and a brake light wire to splice into. Basically, you'll need a plug and cable with the colors labeled as to which goes to which.
I ran my wire harness through the already existing but plugged with a rubber stopper middle hole in the rear trunk, so it comes out in the rear air diffuser, then run along to the hitch itself.