I presume this is a Dart. There are 2 types of clips plus the screw in front. There are clips that are attached to the trim with studs that stick through the body and have nuts on the back that are accessible in the trunk. I'm not sure how far front those type go. These clips can be bought new from a few vendors and the good ones come with the sealing washer that keeps the trim from damaging the paint on the outside.
Going toward the rear from the visible screw are 3 screws with odd shaped heads that the pillar trim pops over. These screws are not available. I just replaced the fasteners on the 70 Dart I am working on and ended up buying extra clips like the ones that run beneath the back glass. If you drill out the holes for the odd screws you can substitute these for the odd screws, but be warned it is a real pain to get nuts on them and get them tightened - I believe that is why Mopar used these screws. On the assembly line, you would never take the time to climb in the trunk and get to obscure studs to install the nuts.
To get the trim off the odd screws, MAKE SURE the nuts on all the ones with clips and nuts have been removed, take out the front visible screw and starting at the front put something soft (small plastic paint scraper?) under the top of the trim and pop it off one screw at a time (3 on each side). since you haven't finished the paint above the trim you could even use a flat blade screw driver. You might have to rework the locations around where those screws are before you put the trim back on, but it's all on the back side of the trim.
Wish I had taken some shots before I took those fasteners off the car. If you want pics of the clips and the odd screws post again, but I won't get to it until tomorrow.
