Complex sentence: He served as deputy director of developments for Special Warfare, Office of the Chief of Research and Development from 1961 to 1964, and then was reassigned to the office, Deputy Chief of Staff for Operations as Director of Special Warfare.
Split into simpler sentences: He served as deputy director of developments for Special Warfare, Office of the Chief of Research and Development from 1961 to 1964. He was then was reassigned to the office, Deputy Chief of Staff for Operations as Director of Special Warfare.