Bottom trim, nonofficial answer: The bottom trim is held on by brittle plastic (un-nylon like) squeeze clips that slides in a channel in the trim. I have a broken one in my hand from my son's 944. You may be able to wedge out the clips by pulling on the trim, one clip at a time starting from about 4" from the end of the of a trim piece. To have a better chance of salvaging them, gently squeeze the clips together from inside the door panel using pliers. They don't seem to give at all with finger pressure. Either way there is a high chance of breakage.
Top trim: I think is held on by magic. :o)
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Tom F