GM Service Manual Online
For 1990-2009 cars only

The driver side floor mat is held in place by two snaps and the passenger side is held in place by one. To remove the floor mats, pull up on the rear of the mat to disconnect from the snaps. To reinstall, line up the openings in the floor mat over the snaps and push down into place.

Be sure that the driver side floor mat is properly placed on the floor so that it does not block the movement of the accelerator pedal.