How do I remove the counter shaft nut? I see two small detents or impressions in the nut. I presume this is designed to stop the nut from backing off while riding. Can I just use an air impact to reverse the nut off or is there something in need to do first like pry up the two impressions. My local dealer said the manual said to “remove and discard the nut” no mention of the two impressions. Maybe im over thinking this?