GCC,
If you can angle the pivot of the mirror far enough to one side you should be able to get a flexible screwdriver behind the glass to remove the two screws that hold it and remove the whole assembly. One screw on each side.
I sprayed the screws with some PB Blaster and let them sit over night. I had two sets of mirrors. Two worked beautifully and the other two I had to break the glass to remove the screws. Replacement glass is available on ebay. Here is a picture of the screws. Hope that helps.