John Deere has a reputation for building quality equipment that lasts a long time, and their string trimmers are no exception. But the string on a John Deere trimmer will need frequent attention if you have a lot of grass and weeds to cut. Keep the trimmer head away from wire fences if you want to get the maximum life out of your string, and carry extra line with you if you're working a long way from your garage or tool shed. To wind fresh nylon trimmer string onto the line spool of a John Deere trimmer, you won't need any tools other than your hands.
Screw off the retaining knob at the end of the bump head by hand. Lift the empty spool out of the head. Remove any remaining bits of old line from the spool.
Push about ½ inch of new line into the hole in the inside middle of the spool. Wind the line onto the spool, going in the direction indicated by the arrow on the side of the spool. The windings should be snug, but not as tight as you can pull them. Cut the line when the spool is full, holding the line end with your hand so it will not unwind.
If your trimmer has dual strings, repeat with the other string.
Slide the spool halfway into the bump head, oriented the same way as it came out. Feed 2 to 3 inches of the end of the string through the hole in the edge of the bump head. Repeat with the other string, if you have dual strings.
Slide the spool all the way into the bump head. Secure the spool with the retaining knob. Pull the ends of the string out of the holes to remove any slack, and get back to work!