Measure down one inch from the top edge of the top window casing board on both sides of the transom window frame. Mark the measurement on the casing board with a pencil.
Position one window blind mount on each pencil mark. The outside edge of the window blind mounts should be a quarter-inch in from the ends of the top window casing board.
Use a screw gun to drive the screws included with the window blind through the holes in the window blind mounts into the top window casing board. This will secure the mounts in place.
Slide the window blind assembly into the mounts, so that the ends fit in place inside the mounts.
Slide the window blind mount covers into the slots on the front side of the mounts; this will hold the window blind assembly in place.
Lower the window blind down to the desired length, and pull the cord to the side to lock it at the height. Blinds are adjustable, and you can open or close them by rotating the rod.