2005 Patriot Thunder; one of the loop cords that raises and lowers the black out shades (roman shades?) broke. Trying to repair but I can't get the window valance off as I can't get to the upper mounting bracket as the head rail for the shades block access. Can I remove the shade without taking the valance off? On our shades at home, the head rail clips into brackets, twist the headrail and the shade comes out. I felt for but could not find similar brackets in the Beaver. Each window has two shades; a day shade operated by a pull cord and a black out shade which uses the loop cord. Two shades, two headrails, not much space up there to figure things out. Any ideas?