The tailgate of my well-used '83 245 is getting harder and harder to close. It used to close OK, then it needed an occasional slam, then more frequent slams, and now it rarely closes at all. What should I look for to remedy this condition. Also, I assume I will need to get into the guts of the latch through the trim panel on the inside of the tailgate. I am not sure how to remove the plastic inner latch pull to get the panel over it. It looks like it is just a close fit over the steel arm but I've had no luck trying to wrestle it off. Thanks much.