Complex sentence: Margas experienced the most successful period in his career with his first club Colo-Colo where he was part of four league championship winning squads, and was part of the famous Copa Libertadores win in 1991, as well as two other international tournaments.
Split into simpler sentences: Margas experienced the most successful period in his career with his first club Colo-Colo, where he was part of four league championship winning squads. He was also part of the club's famous Copa Libertadores win in 1991, and also won two other international tournaments.