WARNING: This page is about a different car, the 2003 GMC Sonoma, 2003 GMC Jimmy, 2003 Chevrolet S10 Pickup, and 2003 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.
Use a flat-bladed tool in order to pry the step pads upward.
Fig 1: Using Flat-Bladed Tool To Pry Step Pads Upward