Firmly grip both sides of the battery jacket. Hold them at a low angle, but up high enough so they don't snag on any logic board components or the frame.

Slide each end of the jacket toward the top of the battery in a sawing motion to cut through the bottom portion of adhesive.

It might take a lot of back and forth sawing motions before the adhesive comes loose. If the jacket rips, skip down two steps for an alternate method.

Stop sawing when the jacket reaches halfway up the battery.