Re: Disassembly of DP1m - Remove Battery Sub-chassis
REMOVAL OF BATTERY SUB-CHASSIS
Once the heat sink plate is out, you are presented with some confusion, as the next step is not clear. I figured that the various plastic and metal pieces, and a small circuit board, were all part of one item, which I will call the battery sub-chassis. The battery sub-chassis is mostly plastic, and once you recognize this structure, you can find the screws that hold down that plastic chassis into the camera.
Four screws hold the battery sub-chassis, one of them external through bottom of camera.
Remove: one screw that goes through the bottom of the front camera body/shell, another screw that goes into the lens/sensor chassis, and two screws at the top of the battery chassis. Disconnect one small data cable from the small circuit board (again a tiny hinged affair locks down the ribbon).

Two small wires connect the TOP circuit board to the speaker at left side of camera. They are taped to and physically interfere with removal of the battery chassis. Cut the tape with a knife, to free the wires.
Don't cut the wires. Cut the tape that holds the wires, to free them up out of the way.
Then finagle the speaker out from behind the lens/sensor chassis, giving some extra play in the wires. Now the battery chassis can come free of the rest of the camera, albeit again with some finagling and wiggling.
Battery chassis is out all in one piece. It is part of what holds the camera top plate in place.
As is typical in this world governed by Murphy’s law, the circuits and actuators that are most likely to need service can only be accessed by first removing all the other components of the camera (the ones least likely to need service). Thus this very simple and practical modification has required the nearly complete disassembly of the camera! Fortunately, the innards of this camera appear designed / engineered well, so if one proceeds with care and patience, none of the disassembly is particularly difficult.