Removal of gloss black door pillar trim

[rosco]

Can anyone tell me how to remove the gloss black trims that are fitted to the doors. There are 2 on the rear doors and 1 on the front doors. I have a corrosion problem on the bottom of the front one on the o/s rear door. I have posted a separate thread for advice on how to remove the rubber coated chrome trim which runs along the bottom of the windows; this needs to be removed first but I am unsure as to how the gloss black trim is removed. I will be replacing with a new item but need to minimise damage to the rest of the door/window.
Any info gratefully received.
Thanks in advance