Whats the best way to remove the Mustang bumper inserts? I want to put on the metal ones but I need to remove the cheap ones I got first.

 

Just use a hairdryer to heat them up, they will come off pretty easy once heated. Then just use some adhesive remover or Goo Gone to take off any remaining residue. Make sure you use some rubbing alcohol to completely clean the surface before you put on the metal ones.