Ensure that the trimmer is turned off before you attempt to change the line. Disconnect the spark plug wire to prevent it from accidentalyl starting while you are changing the trimmer line.
Remove the line guide plate and old line from the base of the trimmer. Twist the guide plate and pull it from the trimmer. This will expose the cutting head on the trimmer.
Pull the old line from the guide plate.
Wipe dirt and plant debris from the exposed cutting head and the guide plate with a damp cloth.
Replace the guide plate in the cutting head. If you have a Hassle-Free Plus cutting head, slowly turn the guide plate while pushing gently inward until it slides into place. Do not force it into place. If you have a Hassle-Free cutting head, look for the arrow on the glide plate and the letters "A" and "B" on the cutting head. Match the arrow with the "A" if you are using medium or large line, and with the "B" if you are using small line; and push the guide plate into place.
Look for two side-by-side holes on the positioning tunnel between the top of the guide plate and the cutting head. Place one end of the line into the first hole and the other end into the second hole.
Push the line through until the ends emerge from opposite sides of the positioning tunnel on the other end of the guide plate. Pull the ends until the line rests against the side of the trimmer head. As you pull the line through, ensure that the line is an equal length on each side of the trimmer.
Find the two side-by-side holes directly opposite the first set on the positioning tunnel. Repeat the line installation procedure to install the second line.