Here is how you remove a JK Wrangler grille in under 14 minutes. If you won a JK Wrangler you may have to remove the grille from time to time. In this case it was removed to PlastiDip the grille in a matte black finish.
Other reasons you may remove the grille is to get to the radiator, install lights in the back, put in a grille insert, or change it out completely. In any event it might be a good idea to get some fasteners to replace them as you need to.