My daughter shattered her screen 2 weeks before she was headed off to college. I had heard from a friend who had used ifixit to repair several phones, so I thought I would give it a try. Also, another daughter had a similar phone, also with a shattered display, that we had replaced a while back. I hoped to bring them both back to life.
Pretty well. The ifixit guide was very thorough and all of the pictures and step-by-step instructions (and user suggestions) made it seem very doable before I even started. In addition to the display, I had to swap the button from the old display to the new, but ifixit also had a guide for that. The only trouble I had was getting the connectors lined up when installing the new display - they are so small, and my eyesight is not so good. I probably could have done the repair more quickly, but the connectors took me a while to get aligned.
A magnifying lamp would have been a big help when attaching the display ribbon-cable connectors. I didn't have one - I ended up using a head-mounted LED flashlight just to get more light on the subject, which helped me see the connectors a little better.
Also, the screws are SO tiny, and not all the same size. The guide mentioned the importance of using the right screws in the right holes. I used small paper cups with the screw sizes written on each, to keep track of which was which.