If the valance is too wide to fit within your window sill, follow these simple steps to cut it down.
1. Mark with a pencil where you want to cut the valance. You can either measure your window and cut the valance at 1/8" under the width, or just simply put the valance up to the window and make a mark 1/8" shorter.
2. Place the valance in the saw and line it up with your mark
3. Cut the valance. Go slow to prevent chipping.