Complex sentence: A planned upgrade of "Sydney" to a similar standard was cancelled, and she disembarked her air squadrons on 22 April 1955, reverting to a training ship role until she was paid off to Special Reserve in Sydney on 30 May 1958.
Split into simpler sentences: A planned upgrade of "Sydney" to a similar standard was cancelled, and she disembarked her air squadrons 22 April 1955. She took on a training role within the RAN fleet, until she was paid off to Special Reserve in Sydney on 30 May 1958.