2 - 5 minutes
The home button was unresponsive and after 6 months of AssistiveTouch, I was fed up!
Let me first say that the repair was successful without any hiccups.
However, I was NOT prepared for the gruelling 2 hours that this repair took. This experience is a brilliant test of patience; you may discover some things about yourself!
The instructions were thorough and exact, but there's no set of instructions that can make this process easy. Don't pretend you're a tech wizard and internally say "I got this" as you order. Heed the warnings on the page; this repair is DIFFICULT and TIME CONSUMING.
The new home button is as good as new. It gives a crisp click and commands your current app to minimise as smoothly as the sun sets (but way faster).
1. Get yourself a piece of A4 paper and section off and label each set of screws and parts: keep them together and in order! (THERE ARE A CRAP LOAD OF SCREWS, AND MOST ARE OF VARYING SIZES)
2. Persist. Be strong my friend, you can do this. If you feel like giving up and throwing your phone out the window, plough on. If you feel like crying, plough on. Soon your home button will be as good as new.
iPhone 4 Replacement Battery
iPhone 4 (GSM/AT&T) Blank Rear Glass Panel
iPhone 4 Home Button Assembly