So ryan was totally right. The holes are there, and you can access them easily if you remove the bumper skin. I still don't see any way to get to the second one (the one labeled #3 in the pictures below) without removing the bumber skin.
Removing the bumper skin wasn't too bad. It was a bit of a pain, but it made installing the wiring harness correctly quite trivial. Aside from the clips that ryan mentioned (i.e., the ones behind and under the tailgate) that are similar clips behind the fenders. I have taken pictures of where the clip is:
And here are some pictures of the actual wiring install. Maybe with seeing where the holes is someone can figure out how to install the wiring kit without removing the bumper skin:
I added my own zip tie on the end near the tail light. It probably wasn't necessary, but I did it just to be safe so that the wire couldn't get anywhere near the weight.
By the way, I couldn't get the second clip in the picture (labeled #3) to fit into the hole. I don't think there is any question that it is the right hole; the clip was just too fat for the hole. I remedied the problem by squeezing the clip with a wrench to make it a bit more narrow.