Refilling the string in a trimmer--also called a weeder--is often frustrating and when you think you're successful, it jams up on you when you go to use it. For this reason and as a safety precaution, it is always best to follow the replacement instructions that came with your specific trimmer model. However, many trimmers have similar instructions like the basic instructions below. Before replacing the string in any trimmer, you must turn it off and unplug it if it is electric.
Remove the cap which is usually located at the bottom of the cutter. This is often done by turning it either clockwise or counterclockwise, depending on the trimmer.
Remove the circular disk, also called a spool. There may be a button to release it.
Take out any remaining string remnants inside the disk. A needle nose pair of pliers may help with this step.
Cut two pieces of string as long as your manual states, usually around 6 to 9 feet. Some models require only one string.
Insert one end of the string in the upper anchor hole of the top spool and spin the spool to wind the string. Follow manufacturer directions as some require spinning in a clockwise direction while others require spinning in a counterclockwise direction. Leave about 6 inches extended beyond the slot (a small slit where the string comes out of the spool to trim). Alternatively, some models require one string that is folded in half and then inserted in the anchor hole where the ends are folded and then wound together.
Insert the other string (if applicable) to the lower anchor hole of the spool and wind the string as described in step 5.
Replace the spool and cap. Be sure it is on tight before using your trimmer.