Has anyone ever replaced...

...the metal channel that the door window is mounted in? I'm talking
about the piece on the bottom of the window that the winder mechanism
slides in.  I have one spare side window, but the bottom channel is a
bit rusty, and a good channel with the remnants of the side window still
in it. I'd like to swap the good channel to the good glass without
breaking the glass.
 
TIA
 
-=Chris