Removal Procedure

Lower the headliner. Refer to Headliner Replacement in Interior Trim.
Disconnect the GPS coax from the antenna.

Fig 1: View Of GPS Coax & Antenna
Courtesy of GENERAL MOTORS CORP.
Slide the GPS antenna forward toward the front of the vehicle.
Remove the GPS bracket fastener and remove the GPS bracket.

Fig 2: View Of GPS Bracket & Fastener
Courtesy of GENERAL MOTORS CORP.