It was pretty easy for me. My 10 year-old son did most of it for both my and my wife's iPhone 5. First one took about ten minutes, the second about 2 1/2 minutes. Had to pry out the old battery using a dull kitchen knife. A little trouble snapping the glass front in on the first time because I didn't angle it in enough and get the latches to hook in the case. Had to pry everything out and try it again. Second phone went perfectly.

Especially liked that the tools that came in the kit from ifixit.com were lightly magnetized to hold onto the teeny tiny screws. The kit was a great deal! Both batteries I ordered had enough charge to turn the phone back on and verify the repair went well. Thanks, ifixit!