WARNING: This page is about a different car, the 2002 Pontiac Montana, 2002 Oldsmobile Silhouette, and 2002 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Front Adjustable Hood Bumpers
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.