I have a 1969 olds cutlass s convertible. I want to replace the window channels. Do I to remove the windows to do this?

 

Are you referring to the window sweepers/fuzzies that mount at the top of the outside door skin and press against the outside of the glass?

If so, NO, you don't need to remove the glass. You'll need to remove the door panels and loosen the window "stop" pucks/blocks that prevent the window from going lower inside the door. Once you lower/loosen/or remove those lower window stops you can crank the window down low enough inside the door shell to get a straight shot at all the phillips head screws that hold the sweepers on.

 

Yes thats what I am talking about, thanks.