Remove the 2 black screws (Phillips, 3.6mm) at the left and right side of the bottom cover.

Remove the black center screw (Phillips, 7.1mm). Remove the bottom cover. Some rubber might fall off, which usually sits at the battery compartment door to keep pressure on it.

Remove the screw (Phillips, 3.7mm) from the battery compartment (the negative pole).

Depending on how your camera was assembled, you may need to desolder this wire if the screw is blocked.