You should apply to the Family Court of Australia to make court orders by consent (agreement). This makes the agreement final and binding on each of you, which means that neither you nor your partner can make a further property claim from the other in the future.
You will need to complete forms setting out the details of your agreement and providing financial details of who is going to get what. The court has to be satisfied that the agreement you have reached is fair in your particular case. You do not have to go to court if you apply for consent orders in this way.
You can get a Consent Orders Kit, which contains the necessary forms and instructions on how to complete them, from the Family Law Courts website.
You can also get a copy of this Kit from the Family Court registry at the Owen Dixon Commonwealth Law Courts Building, 305 William Street, Melbourne VIC 3000 or by writing to the Registrar, Family Court of Australia, GPO Box 9991 Melbourne 3001 and asking for the Consent Orders Kit and supplement.
Before you sign your documents, you should both get independent legal advice about whether it is a fair agreement in your particular case.