2 - 3 hours
My power button was stuck down - no amount of pressure would make it work. I read in the notes that the problem was likely the power cable, not the button itself, so that's what I ordered.
It took about an hour - I was nervous, first time, you know. The directions and photos were excellent. Even the warnings about things that might get lost or damaged in the process.
Re-installing the cable was tricky. It ships flat but has to be contorted pretty good to get into place. Go ahead and buy a new earpiece - the sticky gets undone during disassembly. I had to plug in the cable then roll it over to plug in the bracket and slide the ear piece into the loop of ribbon. It was awkward but works fine. I labeled a piece of paper with the screw sizes - there are about 8 different ones. When I took one out, I taped it to the paper. Reassembly was a breeze because I was confident I had the right screw for each spot.
Thanks y'all @ifixit, saved me some coin and got my phone back in business! Tom