WARNING: This page is about a different car, the 2008 Chevrolet Malibu Classic. However, it is still accessible from the selected car via links, so may be relevant.
Position the front fender liner to the fender.
Fig 1: Identifying Push-In Retainers In Front Fender Liner
Courtesy of GENERAL MOTORS CORP.
Install the front fender liner with the push-in retainers.