My son dropped the iPad (in the case) on a tile floor and the screen shattered from one corner.
The first screen that I received went on relatively easily after reviewing the guide. When I pressed it into the bent corner, I must have misaligned it, because it snapped and broke again.
I was devastated, but after emailing one of the reps at iFixit I was given a code for a discount on a 2nd attempt.
The second screen arrived and this time I was very careful to clean out the bent area and bend/shave away anything that might be in the way of the glass laying down.
The glass aligns in a tiny black plastic channel all the way around the case. This must be perfect or it won't install properly. If the black plastic is damaged, it's best to cut it away rather than part of it fold up under the glass.