Upon visiting the Apple store to complain about the useless power button that mysteriously stopped working on my iPhone, I was told that my only option was to purchase an expensive "out of warranty" replacement. Fortunately, after researching the problem, I chose to buy a repair kit from iFixit instead!
The repair process went well, although it was nerve-wracking trying to make sure that I didn't lose any of those tiny screws. It took about two hours, but that included redoing a few steps that I didn't get quite right the first time around. All I can say is thank you so much for the detailed guide! I have a working power button now!!
Definitely need a lot of light to see what you're doing. I'd recommend a head lamp. :)