I mounted mine in the center of the spare tire mount. Above the tire blocks the view of the bumper, below (in the bumper) doesn't offer a good enough view in my opinion.
In the center if the spare tire is a perfect spot IMHO. Its an easy install, sorry I don't have any pics up now and my truck is in unavailable to me for the next week or so.
So, the best way I can describe it is to find a bolt that passes through the hole in the center of the mount for the spare tire. I got min 3" long (if I recall) and got a couple nuts and washers to mount it, lock it down and mount a bracket to hold the camera.
I put the bolt through the hole and used the nuts to adjust the depth/distance I wanted the camera to extend past the tire. The cable for the camera is easily run behind the spare, under the plastic on the rear door, into the rubber "tube" into the passenger compartment, through the wheel well (where the jack in mounted), along/under the driver side door sill, into the dash and up to the Kenwood unit.
I'm sure that this description isn't good enough, again, sorry for not having any pics to show. I'll be able to post pics after Thanksgiving but I'm sure you won't be able to wait that long before you install it. I think that there is another member who installed it like I did but I don't recall their name. A search might bring up some results under "back up camera install"...