Sorry, no pictures... but a nice young lady brought over her Mirella today and we took the motor out and cleaned it. We both puzzled over how to get it out, and she said she'd found nothing in the way of help in her Web searches, so thought I'd share this here, as best I remember.
Start by taking the bottom off the machine, four screws. You'll see the motor once you've got that off. It's attached to a black plastic plate with three screws (each with two washers). One of the three is longer than the other two, make note of which it is. Unscrew these three screws and take them and the washer sets out, being careful not to drop any of them down in the machine.
Now wiggle the motor (on its mount) out far enough to get to the two screws in the bottom of the mount that hold the motor to it. You'll need to wiggle the black plug receptacle (which is integral to the black mounting plate) out of its hole to turn this assembly. Take out the two screws and their respective washer, again being careful not to drop anything into the machine. It'll be tight due to wires holding things in.
The motor is now free of the mounting plate, and you can take off the black inspection plate on it (two or three screws) to get at the commutator. Take the brushes out to inspect, then clean the brush chambers and commutator as described in the section on Cleaning a Nova Motor.
Now put it all back together.