Chosen Solution
I have a Samsung Galaxy S7 and a iOpener and am unable to get the back glass off of it, I am heating the iOpener in the microwave for a minute and put it on the left side of the back glass for 3 minutes. After that I use the suction cup that came with the iOpener on the left side without touching the rounded edges. I am unable to get it open at all, not even so much that i can get something thin inside to pry it open.
That microwave thing is a joke if I’m honest. If you haven’t got a heat plate, use a hair dryer. Biggest friend removing the back glass, or any glued glass on a device, is a drop of isopropyl. Softens the adhesive up lovely paired with heat. Just a couple of drops now and then, it’ll evaporate out, but too much, can cause other issues.