I just replaced Jen's iPhone battery

Jen's iPhone, which is approaching two years old, has lost its ability to hold a charge. The battery would lose 20% of its power per hour, just sitting in standby. So I went on-line to buy a new battery and installed it last night. The process was much simpler than I had expected, although you must be able to manipulate some extremely tiny screws in the process.

The instructions I followed are available here.

I bought a battery and matching toolkit (two small screwdrivers, plastic pry-tool and two tiny Phillips-head screws to replace Apple's annoying pentalobe screws,) from iFixit for $30. It took about 10 minutes (not counting the time to sync and backup the phone) to complete this repair. Far better than sending it to Apple, who would charge $80 and hold on to the phone for a week.

All of our battery problems appear to have gone away, thanks to this relatively simple fix.