DOOR mirror glass removal

HI, regarding the mirror glass in a Rallye mirror. Does anyone know how the glass is bonded onto the swivel plate? Obviously I don't want to break the glass. I need to get inside to fix the body. Anyone done it successfully before or know what type of glue or whatever is used? I was thinking of carefully heating up the area, to something like a very hot day,,, and whatever bonding stuff is in there would be softened up enough to carefully pry the glass away. That's what i'm thinking, but anyone who has done it would be helpful. Thanks
Author: 70Hardtop