The adhesive is very strong and I was initially worried about damaging the phone by prying so much. There are a couple of places below the volume switch where you can pry between the metal of the case and the battery. If you lift the battery just a little, wiggle the pry bar further in and then start moving down the case. Don't worry about bending the battery, its dead anyway.
Do not pry on the left side (circuit board side) and do not use the pull tab until the adhesive is broken loose.