Auto Parts: Mitsubishi front license plate holder, vise grip, license plate holder

Question
Why can't I remove the front license plate holder. The screws just turn. Is there a hidden nut?

Answer
    There will be a 6mm nut on the back of the bumper.  It's usually held in place with something, but not real well.  Reach your hand back there until you find it, then use pliers or a vise-grip to hold it while you remove the screw.  Put a dab of oil on the screw when you re-install it so that it won't rust or corrode.