Replace the old bumper trim with the new one. Before you push the bumper tabs in turn on the truck and make sure everything is connected correctly.
push the tabs in and replace the screws ONLY. Do not replace the blind rivet at this point. If you do you will have to take a trip to a dealership to buy two new rivets!
Once you have the bumper trip panel in place and secured minus the rivets attach the trim cover piece. It has tabs that snap in easily. The last pic shows the trim cover in place.