[RickM]

I have several of these mirrors in my house....5 x10s actually.
To remove I supported the face of the mirror with a frame made from a couple of 2x4s and few cross members. I then used a long thin prybar to gently wedge the mirror away from the sheetrock. When it comes free from the wall two helpers walk the mirror back to the floor which is supported by the frame. It's not easy.
I have a stack of these puppies in an unused room. Wonder if I can get them onto the ceiling...lol.

I was going to call a couple of glass places as well for the mirrors and for a few very thick plate glass windows I'm going to remove....Hmmm

The local Want-Ad press type publication is probably best for getting rid of them. Maybe make a few bucks as well.