I finished the battery reinstall successfully, but it took me quite a while. Final thoughts:

1. try heating underside of phone with hair dryer before attempting to pull adhesive strips from under battery. Might help, though I didn’t and ended up using guitar string under battery.

2. buy a really good set of small philips screwdrivers. The set that came with the kit removed the tiny screws fine, but reinstalling the screws was impossible for me without a pro tiny philips.

I watched the video and tried pulling from the side, no dice. Both strips broke and were irretrievable. After trying dental floss and heat, I pulled the small e string off my electric guitar and wound each end around a pencil. This was so the string didn’t dig into my hand while I used it to slowly “saw” the adhesive off from underneath. Alternately heating and sawing from one end and then the other (make sure the string doesn’t snag on anything while doing this, and also make sure the string doesn’t twist into a loop), I was able to cut through the adhesive and remove the old battery. It was quite a chore, but this was the only thing that worked for me. The adhesive strips were laughing at my puny attempts with plastic cards.

I had no problem using suction cup - put zip tie around phone just in case, but by slowly using plastic pry tool and pulling gently on suction cup from lower left side of phone, it separated quite easily. Keep prying around edges slowly so that you don’t get a big release.