Removal Procedure

WARNING: This page is about a different car, the 2005 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

The Onstar Microphone is heat staked into the left windshield garnish molding.

Fig 1: Removing Windshield Side Garnish Molding At Windshield Frame
Courtesy of GENERAL MOTORS CORP.
Replace the Left Windshield Garnish Molding. Refer to WINDSHIELD SIDE GARNISH MOLDING REPLACEMENT in Interior Trim.