25 minuten - 1 uur
I dropped my iPhone in water. I was lucky and immediately got it out, but some water still got into the dock connector. The phone worked normally except that the battery life was cut in half and some odd ball problems like I couldn't turn the phone off; it would just constantly reboot.
I replaced the home button, battery, and dock connector. The home button was a pain, but I took my time and got it done. The dock connector wasn't as bad, and I actually tried to do it in conjunction with the home button. Unfortunately I stripped one of the screws when removing the old connector, and I had to resort to Crazy Glueing a small driver to it (but it worked). Battery replacement was cake.
Not really; take your time (pretty much the general rule when working on electronics). I think it was worth it though: my phone works like new, and at least for me, a 4S serves all my needs for now so I plan on using it for quite a while longer (at least until the "6S" is released sometime in the Fall of 2015).