Iwg, I installed mine with the help of one of my sons. It takes a strong impact wrench and a piece of re-bar to help with the holes. A tapered bar like what the iron workers use would be better.
#1 loosen the bolts with the trailer hooked up to the truck and then remove all of them (you'll also need a wrench to hold the nuts on the inside of the pin box, sorry I don't remember the size but I think it was a 21 mm)
#2 remove the wires that are attached to the pin box(mine had the electrical box and emergency brake switch. I noticed on the newer trailers, they've moved the box so it isn't mounted on the pin box)
#3 pull the truck out from under the Redwood after removing all the pressure by using the front jacks (it's much easier if you're on level side to side to begin with)
#4 Remove the old pin box from the hitch and then latch the new pin box into the hitch.
#5 With the new pin box in the hitch, back the truck back under the trailer and line up the holes (this is the hardest part). Aline each hole and put the bolts in one at a time (finger tight). I found using the re-bar was necessary. After all the bolts are in, tighten them up and remount the wires.
This ended up in many ways easier than what I had expected and I believe it took only a couple of hours. Someone could probably do it much faster.
SOB "The RV Wiseguy"