WARNING: This page is about a different car, the 2007 Buick LaCrosse and 2007 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Removing/Installing Front Speaker Grille
Courtesy of GENERAL MOTORS CORP.
Align the speaker grille to the instrument panel (I/P). Make sure the logo is facing the driver.