Complex sentence: The other three Australian vessels were decommissioned on 20 November 2014, with the entire class to be replaced by an as-yet-unidentified class of six heavy landing craft.
Split into simpler sentences: The other three Australian vessels were decommissioned on 20 November 2014. There are plans to replace the "Balikpapan" s in Australian service with an as-yet-unidentified class of six heavy landing craft.