1971 Plymouth Duster

Hello to the Forum. I have a 1971 Plymouth Duster which requires installation of new door window sweeps (weather seals). I am looking for advice on how to remove the old sweeps and install the new ones. For example, do I need to remove the door panels? And if so, how is that done. On this car the panels appear to be 2 pieces with the bottom part of the panel held in with screws instead of clips.