The long dining room in my condo has opposing walls of glass; one has a patio door, the opposite wall has a 4 panel wall of floor-to-ceiling mirrors. The 2 mirrored panels on the left of the wall are broken beyond hope of repair. Underneath the mirrors is a white brick, you can see it through the damage. They were applied to the wall on a baseboard at the bottom, with a thin silver track at the top, but also glued on using a black, tarry looking substance. Will they come off undamaged? Should I even try? I'd probably either A) put both in the middle with china cabinets to either side, or B) split them up to use on the ends of the wall- and put a bar in the middle. Will it be cheaper to have them moved, or to buy replacement mirrors? Is it even possible?

The black mastic is pretty typical. The problem is that you can actually pull off the mirror plating if the mastic is adhered well. You can carefully try a commercial heat gun, $20 or so at Harbor freight, by heating the mirror where the mastic is applied, if you can guess where it is. Get the glass hot and VERY carefully apply outward pressure at the bottom. It may soften enough. You should put masking tape across the glass, wear heavy gloves and safety goggles. I have been successful doing that and have also broken some. You can also try the wire method, a thin strong wire if you can get it behind the mirror and then "saw" it down the mirror. Custom sized mirrors are expensive. Try to stay with a standard size. .