Hi Steve, if you've got the door card off you're almost there!
First disconnect the drop glass from the winder mechanism, two bolts can be accessed through holes in the top of the inside of the door, and drop the glass (carefully) into the bottom of the door.
Then undo the two bolts/screws holding the front window channel in place and remove (you may need to ease the window felt out of the channel if it's one piece to the top).
Next, there's a single stainless screw on top of the door frame through a nylon bush, unscrew this and this should allow you to pull the channel back. the rubber quarter light seal should pop out. Then just pull the quarter light backwards and it, with its rubber seal, should come out easily.
Underneath the window seal is a rubber strip that may be glued down. Remove this and check the top of the door for corrosion and treat anything you see. I'd also recommend a liberal application of Waxoyl or similar into the top of the door underneath this aperture and above the interior door opening handles as rot is very common there.
Reassembly is just the reverse sequence.
Guy
