15 minutes - 1 hour
This phone has 2 terrible design flaws, the buttons, mainly the power/lock button, and the battery. The lock button was not responding much, and I had to press harder and harder to lock my screen, to the point where it many times didn't work at all. Very frustrating for a premier Apple phone.
The total job took 30-45 minutes. It's really not that complicated, but the video does oversimply the job. The video is 100% needed to guide you, and give you a visual of all the components, including assembly.
The video missed a few steps. There were a few screws that needed to be removed not mentioned in the video. Didn't take long to figure out though. I also wish the video (or pics) would walk you through reassembly. I had to keep skipping back in the video the guide me the assembly order. Overall not a deal killer, and I'm 100% happy.