Removal Procedure

Remove the standard mirror glass assembly (2) from the housing (1) of the outside rear view mirror assembly.
1. 1.1. Manually tilt the mirror glass assembly inboard towards the vehicle.
2. 1.2. Insert your fingers behind the mirror glass and gently pull the assembly from the housing.
Disconnect the electrical connectors.
If one or both of the actuator shaft(s) (4, 7) come off with the mirror glass assembly perform the following procedure:
1. 3.1. Push the actuator in the direction of one of the two slots of the molded ring where the actuator ball attaches and disengage it from the mirror glass assembly.
2. 3.2. Ensure that the actuator springs (6) are not pushed down on the actuator shafts but are seated in the groove provided.
3. 3.3. Install the actuator shaft(s) (4, 7) on to the mirror assembly power drive unit (5) by pressing and rotating the actuator on to the power drive unit.
4. 3.4. Ensure the actuator shafts are pushed down completely into the power drive unit (5).
5. 3.5. Push the memory plungers (3) into the power drive unit. (If the vehicle is equipped with memory, RPO A45.
  
  Fig 1: Removing Face Mirror
  Courtesy of GENERAL MOTORS CORP.