My son dropped his iPhone5 and shattered the screen. While we were fixing that, I decided to replace the battery as well. Glad I did since the battery in the phone showed signs of swelling and the only extra step involved was removing/ replacing the battery itself.
The repair went well. It did take us a bit longer than the stated time for the screen replacement, but I was not in a hurry and had my two kids "helping". The hardest and most nerve wracking part was getting the old shattered screen off the phone. We covered the screen with tape to give the suction cup something to grip, but it was still tricky to do and the plastic did separate from the metal plate. We had to use the opener tool to pry the plastic ring up slowly until we were able to get the whole assembly off. After that, the fix was pretty straight forward although for some odd reason, I could not get one of the screws holding the battery cable in place to actually come out. Not a big deal since i could just swing it out of the way, but still it was odd. I did use a bit of heat from a heating bag to help with the removal of the earphone cable, the home button cable and the battery. The cables are really thin and I did not want to chance ripping them. The battery had been removed previously I think, so it came out easier than expected. Put the phone back together and everything worked just fine first time so I was pretty pleased!
Take your time and have a clear surface to work on. The screws in there are TINY! Watch the overview video and then follow the step-by-step (they are not exactly the same, so follow the step-by-step if any differences). I ordered the phone repair toolkit (I think) that had several tools and a multi-bin tray which was key for holding all those little screws. We used masking tape in the bins since many of the screws removed in a particular step were different lengths, we labeled the screws with the step number AND length to make it a little easier to put back together.