My iPhone 4 screen was broken after dropping directly on the glass on cement. It broke through the screen and parts of the inner part of the iPhone could be seen. I figured I should repair it before it died a quick death.
I think the repair is listed at an hour with a repair difficultly of "hard." I can attest to the hard part. I had to disassemble the phone twice because I did not follow the instructions. I would recommend iFixIt including a sheet where each screw should be placed because it gets very confusing when you have 20 different types of screws. 2 1/2 hours later, I was done! And it actually works!!! :) Very happy with the end result and the product. Thank you iFixit!!!
Get a piece of paper and label each area with the screws and what step it goes with. It would have made it much easier. Take your time...don't rush through it.