This is from another model response, but I suspect it is probably similar. It may also have latches on the bottom
Once you have all the screws out from the back you want to wack the panel from the bottom towards the top of the tv. Essentially there are fixed screws that the back panel is resting on like a picture rests on a screw in the wall. So you want to push it up in the same plane as the tv panel. If you force the back away from the tv you will break those snaps. There are around 4 or 5 screws across the you inside the cover so it can take a lot of controlled force to knock the panel off the screws.