After using your Weed Eater edger blade over the course of the season it will become dull. Dull blades perform poorly when edging, will rip and tear at your grass and leave a jagged edge. To replace or sharpen your Weed Eater edger blade, you must first remove it from your Weed Eater. Don't worry about this being a challenging task because the blade is easily accessible and you don't have to remove excessive components to access the blade.
Disconnect your Weed Eater's spark plug by pulling the spark plug wire connector off the spark plug.
Insert a small screwdriver into one of the holes in the gearbox. This locks the blade in place and prevents it from turning when you turn the blade nut.
Place an adjustable wrench on the blade nut and turn it counterclockwise. Remove it completely.
Remove the washer and edger blade from the engine shaft. Set the washer and blade nut aside so you can put them back into place after you either sharpen your existing edger blade or replace it with a new blade.