Window blinds can provide a nice, decorative element in any home while also providing the basic function of keeping sunlight from seeping in. There are a few reasons why your blinds might not fit in a window--one being you measured improperly and purchased the wrong size. Blinds can be cut to fit as long as you have the basic tools to do so.
Reduce the size of your horizontal blinds by cutting the valance, head rail and slats with a hacksaw. Determine the new width of the blinds with a measuring tape. Draw a line with a pen where you need to cut them.
Slide the metal end stiffener out of the head rail. Trim the head rail on the line you drew with a hacksaw. Shove the metal piece out of the way with pliers while you are sawing. Squeeze the end of the head rail in place with the pliers and replace the end stiffener in the top rail.
Secure the blind slats with a large rubber band and make sure they are evenly aligned. Cut them down with a hacksaw that has a dull blade to prevent damage. Cover the slats in masking tape to protect them while you are sawing them. Measure the line where you need to cut on the tape and make a mark with a pen.
Measure the place on the valance where you need to trim it and mark with a pen. Saw just inside the line to make room for the metal brackets.
Move the head rail back in place. Hook the blinds back on the wall and check that they are straight and hang properly.