Buy a new starter rope or if you have some suitable rope you can use that. open the starter and be careful the recoil spring does not fly out and hit you. remove the spring and the rope. wind the new rope in and then wind the spring and put it in the starter, again taking care, and close the starter up. pull the starter rope through the little hole and attach your handle.
To start motor, turn on fuel and pull starter cord.

Give us a yell if you have any hassles
RGDS Jacko