is easy to do as i bought new ones from a dealer (i was picky as it has a little green build up round the edge...is in good condition in my garage if your interested). off a t reg (99).
need to remove the plastic trim inside the bootlid and all the nuts/bolts are revealed............
The brake light removal from what i remember was a pain....as my new one didnt come with it i had to remove it from the old one...
Will check it out tonight and post more detail.....
give the paint a good polish when you replace the light cluster.....