iPhone 4s battery life successfully restored

My Problem

Instead of the ~6hrs of battery life that my iPhone 4s used to have, one full recharge only resulted in about 3h a couple of weeks ago.

My Fix

The replacement process was fairly easy and could be done within 10min using the tools and parts provided in the replacement kit. I used a YouTube-video to do it right.

My Advice

Thanks to iFixit, I now have the old battery life of around ~6hrs back. Considering the package with the replacement kit took only about 3 weeks to ship to Switzerland (even with standard UPS mail), I fully recommend using iFixit to solve my kind of problems.