I managed to disassemble and reassemble a battery , combining a dead battery and a battery with a broken housing.
I bought a battery where the internals but not the casing had survived a crash. Looking at the cracked casing I got an idea of how it was assembled. There are 3 assembly clips on each side and 2 on the rear of the battery casing holding the casing together. Besides that the casing is glued together. The battery is glued on the baseplate, and the connector is fixed with a plate screwed to the base plate. On the bottom of the battery there are 2 stripes of foam glued to both battery and casing bottom probably in order to compensate for tolerance and to prevent shock when landing. Each corner of the baseplate has a magnet which holds the battery to the drone.
The disassemble process was to cut the two halves with a Stanley knife, cutting 1/5” deep, then heating the bottom of the landing base with a hairdryer, while breaking the assembly clips by pulling the 2 halves from one another.