Remove the MCD shade from the valance first. Got to the MCD web site, they show how to remove the shade from the clips that hold the shade up. Once the shade is out, the angle brackets that hold the shade to the wall are visible and easy to remove. I used hollow wall anchors where the striped screws were located. T here is foam in the walls so the anchors are a bit difficult to expand. If there is framing above the window, I do not know where it is. If there is, this would be the best place to just screw.
On the MCD site, the instructions are under "videos" and then "How to use the mounting clips".