Jock,
If the mower is a two stroke the starter cord is usually easy to replace providing the pulley spring is ok.
1. Get new starter cord and tie a knot in one end.
2. Turn pulley around about six times clockwise to get tension on spring.
3. Feed rope through pulley hole and then bring it up through eyelet on aluminium housing.
4. Put rope through handle and tie a double knot.
Hope this helps but if you need more detailed information then it is in the parts list and manuals area this forum.
