Troy-Bilt weed eaters are used to trim grass and weeds that grow around objects that the lawn mower cannot get to. A spool that has cable wound up around it rapidly spins and cuts the grass and weeds. The cable slowly erodes when cutting your weeds and it will eventually run out. You will then have to replace the empty spool with a full spool on your Troy-Bilt weed eater to keep trimming the grass and weeds.
Disconnect the spark plug wire from your weed eater to prevent the weed eater from starting up when you are replacing the spool.
Grasp the bump knob and turn it counterclockwise. The bump knob is the knob that allows you to feed more cable out by bumping the weed eater into the ground.
Remove the bump knob, along with the spring and foam seal.
Grasp the empty inner reel and remove it from the outer reel by pulling it straight off.
Cut off the plastic wrap around your new inner spool. Go slow so the cable doesn't rapidly unwind from the reel.
Feed the cable ends from the inner spool into the eyelets on the outer spool. Keep the remainder of the cable tight on the inner spool.
Locate the arrow and push the inner spool on to the outer spool with the arrow side facing toward the outer spool.
Install the foam seal, spring and bump knob in the same manner as they came off. Turn the bump knob clockwise to lock everything into place.
Grab the end of each cable and give it a firm tug. This will release the cable from the holding slots on the inner spool.
Place the spark plug wire back on to the spark plug.