I agree with DJProfessor, I found the best thing to do is, if it's not ripped leave it in there, tape everything off and spray it with a spray bomb fabric spray. I've replaced several. If you want to save it you'll have about an hour in just getting it all out without ripping it or breaking your plastic door light brackets, a waste of time.
(plastic door light brackets are the only
thing I curse BMW for
P.S. I'm going to be selling metal door light brackets soon. B)