WARNING: This page is about a different car, the 2007 Chevrolet Monte Carlo and 2007 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
Disengage the data link connector (DLC) tab (1).
Fig 1: View Of Data Link Connector (DLC)
Courtesy of GENERAL MOTORS CORP.
Remove the DLC from the instrument panel (I/P) trim pad.