That procedure is so easy and obvious that schoolboy of 6th grade could do it without any manual.
But anyway:
Removal
1. Remove the left side cover.
2. Locate the access cut out on the left side, upper left.
3. Remove the power, ground and encoder connections from the motor.
4. Squeeze the torsion spring together.
5. While holding the spring compressed, lift the motor and mounting bracket
up from the supply compartment.
6. Remove the two screws securing the motor to the mount (access to the
screws is through the holes in the drive wheel) and remove motor.
7. Loosen the two set screws securing the drive wheel to the motor and
remove.
8. Remove the ground tab from the motor and retain.
Replacement
1. Reverse the order of the removal procedure
Feeling better now?