How do you replace carbon brushes in a Audi a4 heater motor?

To replace the carbon brushes in an Audi A4 heater motor, first, disconnect the vehicle's battery to ensure safety. Remove the heater motor from its housing by unscrewing any fasteners and disconnecting the electrical connectors. Access the carbon brush assembly by removing the motor's end cap, then gently pull out the old brushes and replace them with new ones, ensuring proper alignment. Reassemble the motor and reinstall it in the vehicle, reconnecting all electrical connections before reconnecting the battery.