Its a bit of a hassle to remove the lining but its pretty easy.
Need to remove all handles, sun visors and sunroof handle console etc. These 6 bolts under the sunroof glass that hold the sunroof slider in that all need to come off and a platic trim across the top of the tailgate. I think thats it, but someone will correct me if i have missed anything.
Then it should drop off. It may be glued in to the roof as well, can't remember. Refitting is opposite of removal.