This is in Windows & Doors (house windows & doors mainly) and may be better in Motor Vehicles, Cars.
If there's a grab handle it will be screwed firmly to the door metalwork - the grab handle needs to come off first. You may have to lever off a trim piece on the handle to get to the screws.
You will probably find three or so screws along the very bottom edge of the interior trim panel - very low down.
After removing these screws pull the bottom of the panel slightly towards you and push it upwards - sometimes a little upwards thump helps it.
Peccavi, July 2009