Removal Procedure

Remove the throttle body air inlet duct.
Use a large flat-bladed tool in order to depress the reverse servo cover (40).
Use a small flat-bladed tool in order to remove the retaining ring (39).
Use a small flat-bladed tool in order to pull the O-ring seal (41) out through the slot in the case.

Fig 1: Removing Retaining Ring Using A Small Flat-Bladed Tool
Courtesy of GENERAL MOTORS CORP.
Use side cutting pliers in order to cut the servo cover O-ring seal (41).
Use a large flat-bladed tool in order to depress the reverse servo cover (40), grasp one end of the cut seal (41) and pull the seal (41) out of the servo cover (40).
Remove the reverse servo cover (40).

Fig 2: Cutting Servo Cover O-Ring Seal Using A Side Cutting Pliers
Courtesy of GENERAL MOTORS CORP.
Remove the servo assembly (42-48).
Remove the servo spring (49).

Fig 3: Removing Servo Spring & Assembly
Courtesy of GENERAL MOTORS CORP.