Unscrew all the screws holding the top cover in place over the engine. Unscrew the bolt on the handle of the mower to remove the starter rope guide, if your mower’s handle is attached to the push handle on the mower.
Take the cover off the mower and let the starter handle retract fully into the starter’s pulley. Unscrew the screws holding the pulley to the top of the engine. Remove the pulley from the engine.
Cut off and remove the rope if it’s frayed or broken. Check the condition of the starter handle and replace it if it’s cracked, bent or broken. Wind the pulley in the opposite direction as the rope recoils back into the pulley.
Wind the pulley until the tension on the recoil spring doesn’t let you wind it anymore. Insert a screwdriver into the center of the pulley to keep it from unwinding.
Thread the rope through the hole on the pulley and tie a knot at the end of the rope. Hold the rope with one hand and remove the screwdriver. Let go of the rope slowly to rewind it back onto the pulley.
Refit the pulley to the top of the engine. Fit the cover back over the pulley and tighten all the screws. Reconnect the starter handle to the mower’s handle if your mower operates this way.