how can i shorten the width of my levolor vertical blinds?

i recently moved & i moved my vertical blinds with me...only problem is the windows are not as wide as my previous home so i want to shorten the width of the blinds to fit the smaller windows...the verticals all have the cords & chains....somehow there must be a way to do this...please help!!!
PATTY, October 2013


done
Depends on make but
http://www.youtube.com/watch?v=5xc3HUe9EX0

Helper, October 2013