I did mine a few months ago.
From memory you have to remove the plastic strip in the middle of the door card, then pull off the large triangular fabric piece, put the window nearly all the way up, tape the window to the top of the door, loosen glass mounting bolts, then lower window mechanism leaving glass taped at the top.
You should then be able to get to the mirror bolt. There an electric connection for the mirror you have to undo. I think there is a hole in the inner skin of the door to put a socket through to get to the bolt.