I replaced all the 5 mirrors on my A54 two years ago.
It was a big challenge to remove the glued mirror from the bathroom at the back. I did it with a string between the mirrors and the wood wall. There is a special thin and coarse string that is special made for it. I did not get it so I use a very thin metal string that was not so coarse. It took me a few hours to remove it.
I have ordered the same glas mirrors in size and glued it with silicon.
Lior A54 #18