The pin that holds the handle on is shaped like a horseshoe. The tool you use just slides behind the handle but in front of the plastic piece. You just push the tool in and rotate the handle if necessary and the clip should release the handle.
A thin screw driver works just fine. Just pry one of the ends of the spring clip (horseshoe shaped piece of wire) off at a time, and then you can pull the handle off. Might need to rock the handle gently as it is on a ~knurled post.
Like was said, buy a tool designed for this. Trust me !!!! I have been playing with cars almost 20 years and have never seen door panels soo tight against the cranks like they are on our 65 wagon. Slide the $5-6.00 tool in, pop it with your palm and cha ching. Jim