Pushing from behind ist the way to go! Most important, be careful not to damage the battery too much and don’t use a metallic tool. If you manage to short circuit th battery it could mean the end of your device and maybe more. A hard piece of wood with a flat end would be best as a tool. For me, a chopstick did it. Remove the four screws that hold down the USB connector assembly and push it out a little to get better access to the back of the battery. There is no need to disconnct the cable! Then place the Flip at the edge of a table so the battery can slip out when you hammer it down. In my case, it needed lots of force. It would have been impossible to get the battery out just by pulling!