The first step is to remove the old step pad. You should take two flat-tip screwdrivers and use them to create a lever for detaching the step pad from its place on the nerf bar. After detaching the edge of the step pad, make sure to put the flathead of one of your screwdrivers between the step pad and the point where it sticks to the nerf bar to give enough space for the second one to be used as a lever in a more effective way. Then proceed to the opposite end and detach the pad gradually until it can be easily removed. Then put the clips on each hole and use a hammer to attach the new step pad to the nerf bar.