WARNING: This page is about a different car, the 2005 Buick LaCrosse and 2005 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Air Conditioning Compressor Bolts And Nut
Courtesy of GENERAL MOTORS CORP.
Remove the air conditioning compressor bolts (1, 3) and nut (2).