25 minuten - 1 uur
My wife's iPhone 4S was experiencing audio issues (no music/video audio, no volume slider). A quick search online pointed to a dirty dock connector. Cleaning the it didn't help and the Apple Store said it was due to "corrosion". The only thing they could do is a complete swap and since we were out of warranty it was going to cost $200 to do it. We opted to skip the replacement, thinking she could "limp along" until the next generation iPhone comes out this fall. I was happy to discover that iFixit had a replacement dock connector available and for only $35.
The repair went very smoothly and took me just under an hour. The battery was slightly harder to get out that I thought, on account of the copious amounts of adhesive underneath it. The second hangup was discovered when the back panel wouldn't slide into place at the end of the repair. It turns out I hadn't correctly reinstalled the speaker housing and it was sticking up a bit and pushing on the back panel.
Make sure you get the bottom edge of the speaker assembly tucked back underneath the lip of the frame. Tuck it under, then lower the side with the WiFi antenna fins into place, making sure you don't catch the fins on anything.