Complex sentence: The pranks they play on each other escalates into ugly and destructive acts, culminating when the jealous Sheila and a friend, Howard, corner Laura on her way home from school and cut a large chunk out of her long hair.
Split into simpler sentences: The pranks they play on each other escalates into ugly and destructive acts. Sheila (whom hates Laura) and a friend, Howard, corner Laura on her way from school and cut a large chunk out of her long hair.