Another general comment about this guide: the photos are very nice, but it would be extremely foolish to open your phone and remove the battery while holding it in your hands, as is depicted. Work on a flat, clean, open table top to minimize the chance of losing any screws or other parts.
This step needs a few more caveats.
The bottom screw on my phone was locked with some thread adhesive, and required more force to loosen it than I expected.
Even after removing the screws, the battery connector was rather firmly seated, and required a fair bit of persistent gentle prying with the opening tool before it came loose.
The ground clip came loose and nearly flew off while loosening the connector, so it would really help people if there were a warning on this step to watch out for the ground clip and make sure it doesn't bounce away.
People should be advised that the screwdrivers provided with the iFixit battery replacement fix kit are slightly magnetized, which was a surprise. So touching anything except the screws themselves with them is a bad idea.