Look for tabs on the side of the larger circle and if you find them, push on the top tab with your thumb and depress the bottom tab with a flat-head screwdriver to release it. Repeat on all tabs until the large circle comes free and then push two additional tabs on the knob head.
Who makes Troy Bilt trimmers?
Craftsman’s gasoline-powered string trimmers are based on those of manufacturer MTD, which makes Troy-Bilt and other brands.
