The battery terminal gave me some trouble reconnecting because it appeared there was an offset by 1-2 mm, it did not line up perfectly the first time. I plugged it back in, and tightened the single screw for the battery, put it all back together and the Mac did not recognize the battery. I took the cover out again, and tried to reseat the battery and the terminal fit properly the 2nd time, and the screw fit in as well. It was recognized after this. Take your time reseating the battery and ensure the terminal is seated properly. I also pulled out the 4 rubber grommets, it did not seem like they helped much and made putting the back cover on harder. I also had to fiddle with the black plastic piece that goes around the middle two cells to get it to sit properly so I could close the back cover.

My adhesive remover looked different, it had a black snout/cap and was already cut. The solution spilt as I tried to remove it, barely missing the MacBook. Careful with this step!

I initially thought the battery connector completely comes off. It does not! In the next step (#6) they explain that you only have to sort of 'unhinge' on its south side and bend it out of the way it so it comes off the connector on the board