Complex sentence: It reached number one on Billboard's Modern Rock Tracks chart in June 1994 and remained there for six weeks before being supplanted by The Offspring's "Come Out and Play" in July 1994.
Split into simpler sentences: It reached number one on Billboard's Modern Rock Tracks chart in June 1994. It remained at number one for six weeks, being supplanted by The Offspring's "Come Out and Play" in July 1994.