To disassemble the 3 parts you've got to disconnect the little ring. Use a screw driver to get the ring loose.
Unscrew 3 screws to open the casing.
Unscrew 4 screws to disassemble the printplate and 2 to unscrew the wiring. Then you can lift the motor out by hand.
To disassemble the motor holders you can slide them of the casing.