Guys, this is an old one that you bumped, but in my case it turned out that the two upper tabs of the screen were damaged, so the screen was protruding until my iPhone's screen got broken when I was on a ride ($@$*!& mount didn't do its job), and then I bought a new screen which was easy to attach to the rest of the phone.
Perhaps somewhere there's a photo that shows all the screws for size comparison that says how many there are of each type? I don't have a digital measuring tool for screws and I don't wanna wait weeks for one to ship from china (eBay). Thanks.
Just did this on my mother’s phone and it works. I hope it lasts.