It's a Venetian blind I guess - the draw strings dangle down one side or another and come together in a common fitting.

Drop the blind to its lowest position - remove the piece that holds all the strings together - pass the draw cords through the locking piece and tie them in a knot and secure them.

Operate the blind - be sure that whoever needs to work the blind can reach the securing piece - if not move it down as required. When content then snip off the excess cord.

Have Courage...
December 2015