Complex sentence: Coughlin most recently served as the head coach for the New York Giants, a position he held for 12 seasons, where he led the Giants to victory in Super Bowl XLII and Super Bowl XLVI, both against the New England Patriots.
Split into simpler sentences: Coughlin most recently served as the head coach for the New York Giants, a position he held for 12 seasons. He led the Giants to victory in Super Bowl XLII and Super Bowl XLVI, both against the New England Patriots.