WARNING: This page is about a different car, the 2003 Buick Regal and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: HVAC Compressor Clutch Does Not Disengage (Steps 1 - 12)
Courtesy of GENERAL MOTORS CORP.
Fig 2: HVAC Compressor Clutch Does Not Disengage (Steps 13 - 16)