How do you remove a broken bolt in a engine shaft of lawn mower?

To remove a broken bolt from an engine shaft of a lawn mower, first ensure the engine is off and cool. Use a center punch to create a small dent in the center of the broken bolt to help guide the drill bit. Drill a hole into the center of the bolt, then use an easy-out extractor to reverse-thread and pull the broken piece out. If necessary, apply penetrating oil beforehand to help loosen the bolt.