with the giant size channel locks grab hold and unscrew it...take it to the workbench to straighten the bent tabs to where it will give you no trouble...perhpaps a spray of tri-flow lubricant~
If it's the cap that's damaged replace it. They're cheap. If its the filler neck that's damaged that can be replaced as well. HTH. -Jim
Looking for a Used Navigator in your area?
CarGurus has 5,857 nationwide Navigator listings starting at $1,999.
Search Lincoln Navigator Questions
Lincoln Navigator Experts