From a repair shop perspective, don’t attempt this repair if you’re a DIYer. I’m all for people attempting their own repairs but there are two methods to repairing the back glass. Either source an OEM frame with small parts and a battery from a donor device and transfer the board, screen, and face ID components or buy a $3,000 laser machine.
This is one of those repairs you should leave to a reputable repair shop as it is very difficult and you can mess up your device quite easily.