do you mean the door stop ??
iff so you may need to remove one or both the side stops to allow it to drop far enough to pull the nails out enough to push the stop back up and hopefully expose the nail head to pull out with a claw hammer or pliers
just be aware a plastic door will let a lot off heat escape and stop little if any noise so try a week with the door wide open in use and that will give you an idea off the problem