I have a friend that works in whole sale repair of screens and all the and 90% of shops are taking the cracked screens to 4 about b2b screen repair outfits.
They have this machine that heats that screen, sucks onto a flat surface and run runs calibrated thin wire to take the glass off. If they get this wrong the screen breaks and there is no chance to fix it If they get it wrong the LCD harvesting is low and the repair cost goes up.