Pry up the rear panel by pulling the dental pick clockwise in a quick motion. Apply force perpendicular to the plane of the display assembly. You may be afraid to go fast, but going slowly is more likely to bend the case.

The rear panel is still attached to the iPhone by the headphone jack cable, so don't entirely remove the rear panel from the iPhone just yet.

Make sure the phone is off before disconnecting the headphone jack cable.

Use a spudger to disconnect the headphone jack cable from the logic board.

Use the tip of a spudger to remove the cloudy white glue covering the battery contacts.

To reduce the risk of shorting the red battery lead to the metal shield, you can first remove the glue from the black and white battery leads. After desoldering the black and white leads, then remove the glue and desolder the red lead.