BE CAREFUL HERE.
Take a good look at that camera loosely sitting there. It is possible that it will be slightly offset when shutting the assembly back into place. This causes it to not properly focus on closeups. If you don't move it around you will probably be okay.
Also, look at the display assembly, it has three small locking tabs that can bend easily if not pushed in at the right angle into the iPhone frame. Be careful not to be too forceful. Good luck.