The iPhone 4 button was becoming very unresponsive. I attempted several of the "fixes" found online including wiping with alcohol, using canned air, and giving it a good know on my knee. Nothing worked and I was forced to use the Accessibility option in order to "push" my home button.
The repair took 1.5 hours and required a considerable amount of patience and concentration. The instructions were marvelous and I used both the step-by-step written out version and the video version.
Buy a magnetic screwdriver that fits these extremely small screws! If I would have had a magnetic screwdriver, I probably would have cut my overall time in half. Disassembling is easy, the difficult part is reassembly!