My son is 5 years old. My son's biological father (my ex) has not been in my son's life since he was a few months old. My ex has made it clear that he doesn't want to be involved in my son's life now or in the future and has asked me to remove his name from my son's birth certificate. So I would like to know is it possible under family law to remove his name from my son's birth certificate and for him to give up any legal rights to my son. Also my fiancé and I have been together for 4 years and he plans on adopting my son. What would be the steps (e.g. Adoption Australia) and costs involved and would my ex have to give his consent?