WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
Install the bulb to the socket.
Install the vanity light lens to the vanity mirror ensuring the retaining tab is fully seated.
Close the cover to the vanity mirror.
Return the sunshade to the folded up position.
Fig 1: Installing Vanity Light Lens To Vanity Mirror