Complex sentence: Live crabs are cooked simply by dropping them into boiling salt water, waiting for a boil to return, and then allowing it to continue for 15 minutes, after which time the crabs are removed and placed into cold water to cool, and then cleaned.
Split into simpler sentences: Live crabs are cooked simply by dropping into boiling salt water, waiting for a boil to return and then allowing it to continue for 15 minutes. After which time the crabs are removed and placed into cold water and then cleaned.