Complex sentence: After a brief firefight they killed 1 Iraqi soldier and captured 13 more, the SEALs secured the MMS and the pipelines; they were relieved by Royal Marines from 40 Commando, the SEALs advising the Marines helped coordinate AC-130 Spectres fire support onto Iraqi forces.
Split into simpler sentences: After a brief firefight in which the SEALs killed 1 Iraqi soldier and captured 13, the SEALs secured the MMS and the pipelines, and were relieved by Royal Marines from 40 Commando. The SEALs advised the Marines, helping coordinate AC-130 Spectres fire support onto Iraqi forces.