I would not heat it. As others mentioned you can create other problems. Plastic putty knife, thinnest you can find in a hardware store and try and get it between the glass and guides. You can use a cleaner or dish soap as lubricant on the putty knife and as a bonus it will stay in the tracks and help with removal. If that doesn’t work try a giant suction cup that can grab the glass and you can put some leverage on that as well