When it is time to replace the cutting line on your Ryobi string trimmer, commonly referred to as a weed eater or a weed whacker, always respool with the correct line diameter for that particular model. The string diameter will be found either in the instruction booklet, or it will always be marked on the trimmer spool itself. Using the correct line will guarantee that your string trimmer will work correctly and efficiently every time.
Remove the string spool by turning the center knob on the trimming spool in a counterclockwise direction. When the center knob has been removed, the trimmer spool will pull out of the spool housing. You will need no special tools to accomplish this.
Determine the string size by referencing your owners manual or reading the actual trimmer spool itself. The spool will have the string size embossed into the plastic, or there will be a sticker on the inside of the spool that will also give you that information. The most common string sizes are 0.80 and 0.95, and depending on the model, one of those will fit your spool.
Locate and then insert the new line into an angled anchor hole which will be found near the center of the spool. Bend the trimmer line sharply once inserted into the anchor hole to keep it in place, then run it along the channel which guides it onto the winding spindle.
Wind the line counter-clockwise around the line spindle, following the guide arrows found on the spindle of every Ryobi trimmer. When you're finished filling the spool, snap it into one of the string holding notches on the outside edge of the spindle.
Snip the string off leaving about an inch protruding as it rests inside the holding notch. A heavy duty pair of scissors or regular garden shears will make a nice easy cut.
Grab the string firmly in your fingers and pull it out of the holding notch. Continue holding the string as you place the spool back into the trimmer hub. When you start to place the spool back into the hub, locate and then thread the cut end out of the exit hole in the actual hub itself. Feed out about 6 inches of lineit doesn't have to be exact, and-- firmly seat the spool back into the hub.
Replace the center knob onto the spool and hand tighten it in a clockwise direction to secure it back into place.