WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: View Of Front Adjustable Hood Bumper
Courtesy of GENERAL MOTORS CORP.
Close the hood firmly.
Determine the amount of adjustment needed.
Open the hood.
Raise or lower the front adjustable hood bumpers as required.