Pull the back pannel up starting at the bottom of the frame. There is a little hinge at inside the frame the top that will move up and make it much easier to remove the back panel (almost without effort)

I totally agree. First strip did not come off. Heated the phone up, second one worked as if I did it every day..

+ You should hear a rattling sound (the strip moving towards the bottom of the battery) while pulling. If you do not hear a sound while pulling it will probably break !