The autofocus on my rear-facing camera would just pulse and never settle on a focus setting.
The repair was easy. There only two sticky points. First when plugging in the display cable, it is kind of fiddly and ended up using my fingers but never got a confident seating like the other cables. The second was putting the cover over all the cables it was very tight on the cables running to the back half of the phone so it was awkward holding the case at an angle to keep the pressure off of the cables while putting the protective cover back on. Other than that. Very easy.
Take your time. Keep your screw organized, i.e. lay them out in a pattern that mimics where they came from. Use magnification of some type. I have a headset magnifier and it really helped when seating the cables.