Turn off the lawn mower engine.
Locate the two control bar adjustment levers. The levers will be where the bar meets the mounting brackets at the rear of the mower frame.
Raise the control bar of the lawn mower slightly. Brace the control arm with your shoulder or ask a helper to support the control bar for you.
Pull the adjustment levers in toward each other. This frees the two adjustment pins on each end.
Raise or lower the control bar to the desired height.
Release the levers, allowing the pins to enter the adjustment holes in each bracket. Make sure the pins are fully seated into the same position holes on both sides.