Both adhesive strips broke despite heating. Then the floss broke. Likewise, here is where I almost gave up. Used an old credit card gently, and bent the battery a little bit with constant fear that I would be starting a fire. Some patience, and with a few minutes, it was out.
Initially thought I would skip these steps, as many people said to skip steps 13-19, but I tried proceeding without removing the front panel, and my adhesive strips simply would not remove, even with heating….so off the front panel came. Putting it back (connecting the cables back) was definitely a little panic-inducing, but managed to do it without damage - definitely watch some youtube videos!