Position a catch basin under the Weedeater and remove the drain plug. Allow all the fuel to drain out of the unit. Keep the drain plug in a safe place.
Shake the Weedeater back and forth several times to remove any remaining fuel. Wait for all the fuel to drain out of the tank.
Reach inside the fuel tank and pull out the fuel filter. Discard the used fuel filter and install a new one.
Replace the drain plug at the bottom of the fuel tank. Add a commercial fuel system cleaner to the tank and add the recommended amount of gasoline. Follow the instructions on the bottle of fuel system cleaner to determine the proper mixture and usage.
Add a bottle of fuel system cleaner to the Weedeater's tank just before you store it for the winter. Run the fuel system cleaner through the tank, then drain the fuel tank completely before storing the Weedeater in your garage or shed.