Complex sentence: His coaching career began for Van Eck as assistant coach from FC Lucerne; in 2003 he was named as the new Head Coach, his greatest success was the climbing in the Swiss Super League, among others with 31 games without defeat.
Split into simpler sentences: His coaching career began for Van Eck as assistant manager of FC Luzern; in 2003 he was named as the new manager. His greatest success was the promotion to the Swiss Super League, among others with 31 games without defeat.