Here's what the part looks like from the outside:
The first step to opening it up is to remove the cover over a section of the drive. Note that this process is likely to cause permanent damage to the part as it requires prying and bending.
We can now slide the gray back cover off.
The PCB is clipped in at the front, but with some care we can separate the gearbox from the motor.
The gearbox houses a pair of bevel gears. The gray one that is part of the drive shaft is 11 tooth and the smaller one is 9 tooth.
With significant force, the drive shaft can be separated to remove it and reveal the magnet that is used to sense drive angle.
Moving back towards the motor, we find a double planetary gearbox similar to the one found in several motors without angular drives.
The motor itself is soldered to a PCB. There's nothing other than traces on the side facing the motor, so I haven't bothered to desolder it.
The main microcontroller appears to be an STM8S103. My part has the following part information:
The other significant visible part labeled
509R is a thermistor that serves to put a hard limit on motor current.
Viewed from the other side, we can see the hall effect sensor that is used to detect drive angle. The part number on mine is