Replace your dying GoPro battery with a fresh one. If you're ready to jump off a mountain, your battery should be too!
Place your thumb on the indentation in the back case on the side of the GoPro.
Gently press down with your thumb and lift the back cover away from the case to remove it.
Slide a plastic opening tool between the battery and the rear case.
Gently pry the battery up and out of the rear case.
Remove the battery from the case.