Thanks Mark, but of course the owners manual really offers nothing on that degree of maintenance, but the link to the video helped loads. I used an air impact gun to remove the bolt on the clutch. I replaced the clutch and made a mistake of shifting the pin that holds it to try to get it lined up and after an hour on the lawn I had a terrible screech. Tore it apart again and found the pin worn about halve way through. Readjusted and back together again, better now.
