How did crusoe escape from slavery after the second voyage?

Eventually they confront the mutineers, telling them that all may escape with their lives except the ringleader 

On Crusoe’s second voyage, Turkish pirates capture the ship and take everyone aboard to the African Moorish port of Salee, where the pirate captain makes Crusoe his slave. One of Crusoe’s duties is to catch fish under the watchful eye of his master, and he becomes an expert at this task. After two years, an opportunity for escape presents itself. One day, the captain stays behind while Crusoe goes out on a fishing boat with two Moors. Crusoe overpowers one Moor, who swims ashore, and threatens to throw the other–a boy named Xury–overboard unless he serves Crusoe.