WARNING: This page is about a different car, the 2005 Chevrolet Optra5 and 2005 Chevrolet Optra. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: View Of Assist Handle Screws
Courtesy of GENERAL MOTORS CORP.
Position the plastic caps to reveal the assist handle screws.
Remove the screws and the assist handle from the headliner.