The extra slat they include in the box is a valance to hide the top bar and mounting brackets. You can fix them.
Open the blind fully, and open the slats so that they are aligned horizontally, not at an angle.
Look at the bottom of the base piece of the blind, and locate the three buttons there.
Place the edge of a small flathead screw driver under these buttons, and pry them off.
Remove the base of the blind, letting the strings hang loose. Remove slats to get to the broken slat, taking note of how the string alternates in the holes of each succeeding slat.
Once you have removed the broken slat, slide the replacement slat (you can use one from the bottom of the blind) into place.
Replace each slat that you removed, taking care to string them as they were before. Replace the base piece, and snap the buttons back in place to finish the job
at 6:47 PM on Jun. 26, 2010