Now that I finally got the power windows to go down, I don't know how to remove the ledge moldings.

Any advice?

Where are the door ledge mouldings? Not real sure what you are talking about. Drip rail mouldings? Or door edge?

the moldings at the top of the door and at the top of the rear quarter at the bottom of the window.

They are called Inner and Outer Fuzzies, or Window Felts. The insides are attached to the door panels. The outsides have little spring clips that slip into slots in the door panel/quarter panel. It's been awhile since I did mine, but I think there's a couple of hidden screws into the door/quarter. Carefully spread the "V" of the fuzzie, and look. Should be about a #4 or 6 phillips screw.

Save them if they are decent--especially if they just have paint on them. Repops are OK, but not like originals. NOS are big bucks!!

I have a 68 RS and it's not the fuzzies that I need to remove, it's the chrome moldings that are attached to the fuzzies.

Does anyone know what they are called (I've heard ledge moldings and belt moldings) and how do they come off without damaging them?

They're belt moldings and they come off the same way.

Remove thew screws at both ends, with a magnetize screwdriver, and then reach inside the door with windows up, and pry out & up on the spring loaded clips to remove the moldings and top stainless.

Save all hardware and patience is the key. There are no attachment from the outside to hold on the moldings, they attach from the inside of the door, along with the two screws.