Using plenty of alcohol (I used denatured alcohol from Home Depot, with an eye dropper) was ESSENTIAL to loosen the adhesive and get the battery out! The iOpener heating pad on the back of the phone for 3 minutes or so also helped a bunch.

I totally agree! Destroyed my OLED screen 10 minutes into the repair as I tried to remove the screen so I could replace the battery. I have now bought ~$100 of tools from iFixit (got them on Amazon for faster shipping) and hope to get this right. The iOpener heating tool looks REALLY useful!—much better than a heat gun, as it uses conduction instead of convection, and can target just where you want to apply the heat!

This sounds like a great idea! I just put a pack of old playing cards in my repair kit. I destroyed my OLED display with a pick too. Hopefully next time I remember to use the playing cards and don’t mess this up.