The drive gear on the motor should fit through a hole in the mounting plate. If the hole is smaller than the gear, it will be necessary to remove the gear from the motor shaft first. To remove the gear, place a piece of tape over the gear and mounting plate. This will help prevent the gear from flying across the room. Using a coin or screwdriver, gently pry the gear up and off of the shaft.
The motor (or gear box) is held in place with two screws. Remove the screws and lift out the motor.
When putting the new motor in place make certain that the drive gear's teeth mesh with the large gear on the front of the mounting plate. Replace the two mounting screws and reconnect the wires.
Before replacing the cover, make sure the shutoff arm is properly positioned to engage the armature. Replace the outer cover, plug in the ice maker and refasten it to the freezer. Lower the shut off arm to turn the ice maker on.