The battery is secured to the frame with adhesive. Pull tabs are provided to separate the adhesive and remove the battery.

Peel the red pull tab away from the top of the battery.

Using one hand to hold the phone steady, use your other hand to slowly and steadily lift the red pull tab up to separate the adhesive securing the battery underneath.

If you're having trouble removing the battery, you can apply an iOpener to the screen side to loosen the adhesive underneath the battery.