10 - 30 minutos
The GF ran her brand new 4S through the wash, and is lucky to be dating an electronics test technician. I brought it to work and through it in the temperature chambers at 40C (I looked that temperature up) for an hour. A couple weeks later, the battery died.
With the awesome help of the guides, I managed to replace the battery (which was pretty distended) and dock connector very easily. Threw it all back together and the phone was overheating like crazy! Back apart, and the control board was covered in deposits, looked almost like dendrites. Hit it aggressively with alcohol, and voila, brand new 4S.
1)Careful prying up the battery, it can rupture if badly damaged and release gas.
2)Don't get intimated, do organize hardware. You won't remember which screws are 1.2 mm.
3)From past experience, ribbon cables tear like taffy.