Here is a universal install for the flaps, https://youtu.be/QckGrDmeJPA. This is on a RAM but the install will be similar on the Silverado. They will fasten to the lip of the fender. You can use either the self tapping screws included or if your truck has factory screws in the fender they can be used to install the flaps.
Verified Answer
Admin answered on 12/26/2019