The motor is fastened to the cover plate and connected by two or three wires. The wires may go directly into the motor or they may be attached to terminals with slip-on connectors. Before disconnecting any wires, label their placement.
One of the motor wires connects to a wire cap. If this wire is connected to the motor with a slip-on connector, disconnect it there, otherwise unscrew the wire cap and untwist the wires.
The remaining wire or wires connect to the shutoff switch near the shutoff arm. The wire is connected to the switch with a slip-on connector (if the wire connects to the motor with a slip-on connector, disconnect from there instead). Firmly pull the connector off of the terminal (do not pull on the wire). You may need to use a pair of needle-nose pliers to remove the connector. Inspect the connector and the terminal for corrosion. If the connector is corroded it should be replaced.