15 minuten - 1 uur
Our one-year-old knocked my wife's phone out of her hand onto a concrete sidewalk and consequently shattered the screen. It's a borrowed phone, so getting it fixed quickly & quietly was the order of the week.
The repair went quite smoothly. Easier than I had hope. I taped the screen with packaging tape (as the comments & instructions note) and popped the shattered display assembly right open.
Getting the cables from the new assembly onto their locations proved to be a bit difficult. The cable length for the camera & sensor cable was a bit longer (maybe ~2mm longer) than the damaged assembly's so it was a bit touchy to get it to sit on the connector properly. After that, everything came together easy as pie.
Of course, my wife didn't bother to test the earpiece speaker (even though I asked her to). The next day I got a couple of "those" texts telling me that she couldn't hear anything. So, that night I'm back to opening it up again to make sure all the connections are seated correctly. Everything looked good but I learned that the speaker contacts are actually only connected via pressure. There's no actual connector. Spent a little time making sure the speaker screws were a bit tighter and pressing the components into place while I closed up the phone and everything is working great.
All in all, even with the second tear down the next day the whole job took _maybe_ an hour thanks to the awesome guides here on iFixit.
The guides are awesome. Read them. All of them. And then glance over the comments. There is good stuff there too.
Also learned (the second time) that you can turn on & use the phone before you close up the display assembly. This allowed me to test that everything was functioning before I finished the work preventing me from having to open it again if the earpiece was still nonfunctional.