Matt,
I seem to recall having to change the rear cluster on my 2003 Sport due to a cracked lense. The plastic trim on the side of the boot had to be removed. This was an absolute pig but it did come off in the end.
I haven't had the pleasure on my 2010 model but it should be the same.
There is a technical manual floating around on this forum somewhere which explains how to do it. Have you tried the technical documents section, it could be in there? If not, I think I have a copy stored on my old laptop if you get stuck.
Farnsy