There two ways to unjam your pencil lead. First, turn your pencil with the tip facing downwards, press the button continuously and give it a good shake, the trapped lead bits should fall off. If this doesn’t happen, theta the lead has probably been trapped in the mechanism. So, push the mechanism down against your table to push back the clutch mechanism. Hold the ring around the clutch shut and push it down to release the clutch jaws to remove the jammed lead bits. Some pencils come with a cleaning rod to make the task easier.