JC is right, the trims are designed to be slid and pulled, but their metal clips rust over time inside the door card.
You neeed somehow to try to gently pry after you slide them (toward the rear of the car), but with something that won't scratch or damage your paint.
I wanted to paint mine and I could not remove them. I gave up and painted them on the car, anyway. You can also remove the door card and push'em from inside, but that would be a bunch of work
