It depends on your model. You can visit the PIVOTRIM website and they show how to install their head on most units which includes how to take your old one off. Their website is http://www.pivotrim.com Otherwise you need to look at your operators manual or call the manufacturer. Good Luck!
sthilweedeaterhead number f5556
To replace the head on a Husqvarna weedeater, first, ensure the engine is off and remove the spark plug wire for safety. Use a wrench to hold the spindle in place while unscrewing the old head by turning it counterclockwise. Align the new head with the spindle and screw it on clockwise until secure. Finally, reattach the spark plug wire and test the weedeater.
The manual can be found at the link below.
stick a flat head screw driver in the slot above head and turn counter clock wise.
To replace the line on a Stihl KM56RC Weedeater, first, turn off the engine and disconnect the spark plug for safety. Remove the cutting head by unscrewing the knob at the bottom. Take off the spool and unwind any old line, then cut a new line to the desired length (typically 10-12 feet). Thread the new line through the spool holes, wind it tightly in the direction indicated, and reassemble the cutting head before reattaching it to the Weedeater.
i need to replace the flex shaft in my weedeater. how do i do it?
To change the head on a 25cc Craftsman weedeater, first ensure the trimmer is off and disconnected from the power source. Remove the old head by turning it counterclockwise; you may need to hold the shaft with a wrench to prevent it from spinning. Align the new head with the drive shaft, push it on, and turn it clockwise until secure. Finally, check that the head is properly attached before using the weedeater.
On most of them you hold the top part with one hand and turn the bummer/spool clockwise (looking from the top)and pull it straight down/outward
pop the spool out wind string in direction of arrow, replace
remove head pull shaft out
To remove the head on a WEEDEATER Featherlight, first ensure the trimmer is turned off and the spark plug is disconnected for safety. Hold the spool firmly and rotate the head counterclockwise to unscrew it. If the head is stuck, you may need to tap it lightly with a rubber mallet or use pliers for better grip. Once loosened, you can pull the head off the shaft.
To replace the pull string on a Toro weedeater, first ensure the engine is off and cool. Remove the starter cover by unscrewing any screws, then take out the spool containing the old string. Thread a new string through the spool, wind it tightly in the direction indicated, and reassemble the spool into the housing. Finally, reattach the starter cover, and your weedeater will be ready for use.