Adjusting day-night shades
Assuming that you mean the day-night shades that are typical:
There is a screw at the bottom left and bottom right of the shades which have plastic 'tie down wheels' for the cords in the shades.
Using a phillips screwdriver, loosen the screw holding the plastic tie-downs in place on one side or the other. Be sure to hold the plastic 'wheel' while you are loosening. You will see where the wheel will pull away from the wall once you have backed out the screw enough. Turn the wheel to tighten the cord as the cord winds around the wheel; not too tightly, but tightly enough that the tension is appropriate to raise the shade and it stays without falling. While holding the wheel in the new position, tighten the screw back down, and you are done. Repeat for the other side.
This is easier than it sounds written out, but hard to mess up except for the possibility of over-tightening the cords and/or the screw. If too loose - no problem - just loosen the screw and re-tighten the cords.
Hope this helps...
2008 Journey 39Z Cummins 350 ISB 6.7L
2006 Honda CR-V LX Tow