Place the plastic opening tool to the side of the battery and work underneath the battery. Slowly and gently pry the battery away from the device removing the battery from the adhesive underneath.

After breaking away one side of the battery from the adhesive strips you can take advantage of the additional leverage by using your hand to break free from the adhesive on the opposite side.

You will hear cracking and popping as the battery breaks loose from the adhesive strips underneath. This is normal and to be expected.