Use an iOpener or a heat gun (on low heat) to carefully heat the back side of the tablet to help soften the battery adhesive.

Use prying tools such as a guitar pick, plastic card, or a nylon spudger to help sever the adhesive and gently lift the battery free.

After the case cools, a careful amount of isopropyl alcohol can help dissolve stubborn glue between the battery and the case.

Work slowly and carefully. Do not pry, bend, or puncture the battery while removing it from the tablet.