[folivier]

You may need to remove the surround panel in your first photo. There should be 2 or 3 screws in the black carpet on the sides. The panel should just come out then you can access the head rail. The blinds should have a screw to remove them from the head rail. You can buy more cord at a blind shop locally or on Amazon. Cindy just redid 1 but I was doing other stuff and didn't watch. I'll try and get some info from her. In the meantime a spring clamp works to keep the blind up