HOW DO I GET LOTS OF THIN SCRATCHES OFF MY UPVC front door?

My Dad has scratched the panels of my white UPVC front door with sandpaper to remove rubber marks but it has scratched the door panels as well as BADLY removing marks! This Is rented accomodation & I want It to be smooth so It looks as good as new again & cannot be noticed!

How do I get the other black rubber boot marks that are still there? Hope you can help me put this right!!