Complex sentence: He accidentally dropped the star that had topped the Trafalgar Square Christmas tree for ten years as he was attaching it to a crane, leaving it slightly damaged; nonetheless, he was allowed to try again once it had been taped up.
Split into simpler sentences: He accidentally dropped the star that had topped the Trafalgar Square Christmas tree for ten years as he was attaching it to a crane, leaving it slightly damaged. Nonetheless, he was still allowed to try again once it had been taped up.