15 minutes - 1 hour
So my lock button had been broken for about a year, and I got around it by using the assistive touch feature on the iPhone, but got tired of it and wanted to get it fixed. My battery life was also getting really bad as well, so that's probably what pushed me over the edge. Having someone else fix it was just too expensive, so I decided to do it myself.
To make sure I fixed my lock button, I changed both the button itself as well as the audio control and power cable. Opening the phone with the suction cup was a little harder than they made it seem in the video, as well as removing the battery, but once those were out of the way, the rest of it was pretty smooth sailing.
Be patient and don't rush anything. Be sure to have a small flat screwdriver handy as it doesn't come with the kit. Be sure to follow the step-by-step guide closely as the pictures help out a lot.