Pull the shade up so it is completely open. Unclip the blinds from their brackets at the top of the window and set them on a table to begin working.
Pull the end caps out from the top and bottom rails. These slide out when pulled with a little pressure. Set all parts aside in a safe place. Repeat on the other side.
Slide the rails off of the window shades by holding the shades steady with one hand and slipping them off their track with the other. Keep the blinds closed as you work. Remove the top and bottom rails.
Pull off any tape on the shades. This is used to hold the strings or weights in place. Save washers for later. You can save the weights as well but the blinds will work without them.
Remove the cord guides and set them aside. The cord guides have an "L" shape and the cord comes out through a hole in the guide.
Pull the strings from the cord stock assembly. Save the assembly for later.
Cut new string by measuring it against the string you just removed. Cut the cord a little longer so you have more cord to work with.
Tie a plastic washer to the end of each cord with a double knot.
Thread the other end of the string through a long, thick needle.
Feed the needle into the bottom route hole on the blinds. Hold the blinds tightly together so the holes are lined up and you can feed the needle neatly through to the other side. The washer should sit flush on the bottom of the shade. Do this for each string hole.
Turn the L-shaped rope guide so it is facing the opposite direction from its original position. This allows the cord to rub on a different side so the guide won't wear out as quickly.
Feed the cord through the cord guide so the peg on the bottom of the guide is facing down. Set the guide inside the route holes on the top of the blinds. Repeat for all the guides and route holes.
Position all the strings along the length of the blind so all lie together on the far right side.
Slide the head rail back onto the track so it keeps the cords neatly in position. The cords will all dangle on the right side of the blind. Repeat on the bottom rail.
Insert the end caps back into position.
Turn the cord lock assembly over so you can see the thread guide underneath. Feed the cords under the guide, toward the hole -- usually located on the right side of the assembly. Press the cords down into the hole so they come out the far side. Turn the assembly over so you can see the cord ends. Feed them through the small, metal bracket.
Pull the cords tight and insert the cord lock assembly into the head rail. The cord lock assembly acts as the final end cap.
Clip your shade back in position in the window and lower the shade.
Measure the length of cord when the blind is closed, to make sure you don't have an excess amount of string. If the string dangles too low, calculate how low you want it to hang, add 6 inches and cut it off at this mark.
Slide a cord cover up the strings so the strings come through the other end. Open an equalizer and place the cords inside. Put the equalizer tab into the equalizer body to hold the cords in place. Put this assembly into the equalizer housing assembly. Attach a thick, knotted pull cord into the bottom of the housing. Wrap the excess lift cords around the bottom of the assembly. Slide the cover down over the housing and trim any excess cords.