I installed the hitch receiver on my 2008 X5. It really isn't that difficult. The BMW instructions are on the site here in pdf format, and the only really difficult part is removing rhe rear bumper fascia. That is only difficult because the fasteners are pretty well hidden.

A member here with the screen name "Ranchhand" has posted a good explanation with pictures here:

http://www.xoutpost.com/x5-e70-forum/...a-removal.html

Cutting the bumper fascia is pretty easy, if you have a saber saw or something similar. The factory installation instructions cover that pretty well. I was satisfied with the rear bumper appearance after the trim strip is installed. I believe the factory instructions cover most of the installation fairly well, except for the removal of the rear bumper fascia (already mentioned), and the location of a couple of electrical connectors in the rear cargo compartment.

You do have to have a LOT of patience to take on the job yourself, though. Once you are through, the dealer has to re-code the car computer for the hitch control module, and also bring up the coding to current specs. That took about six hours on my car, which was only about ten months old at the time.