How can an Australian citizen subpoena information from South Korea?

I'm an Australian citizen who recently arrived home after 5 years in South Korea. I returned home with my South Korean wife and step son. Two months after our return we had a daughter together who, as she was born here became an Australian citizen. Three weeks later my wife evicted me illegally and then told my family, friends and the Australian authorities I had abandoned her. We are now going through divorce proceedings. Relating to our divorce I need information about a stalking case involving my wife and an ex that was settled for substantial damages in mid to late 2005 while we lived in South Korea. My wife claims to have been stalked but I have since found out she sue for breach of marriage promise while she was living with and being supported by me. How can I subpoena or acquire information relating to this from South korea while I still reside in Australia?