Remove the double-clamp piece attached to the top of the wheel shaft. Push the lever to the side to loosen it, then slide the piece off the shaft.
Unscrew one of the clamps, which look like domes with tunnels running through them, from the piece. When it comes apart, remove the collar, then the bracket, which is a short tubular metal piece.
Lay the Weed Eater on a flat surface with the cutting wheel facing the floor. Place the clamp over the shaft of the Weed Eater about 2 to 3 inches above the cutting wheel housing.
Slide the bracket through the holes of the clamp with the threaded side turned up. Press the collar over the clamp.
Line the spring on the double clamp piece over the clamp collar — the part of the piece the clamp was attached to originally. Turn the lever clockwise to tighten it in place, then press the lever so it lays parallel to the shaft.
Slide the wheel shaft through the other clamp. Raise or lower the wheel shaft to the angle desired. Angle it so that the cutting wheel is approximately 2 to 3 inches above the ground for mowing, or parallel to the Weed Eater shaft for edging. Tighten the lever on the clamp.