Ending your marriage legally is only possible through a divorce.
To secure a divorce order, evidence of the marriage needs to be provided, as well as the grounds for marriage breakdown, and, if there are children, evidence that appropriate arrangements have been made.
Under the Federal Divorce Act, you can only apply for a divorce if the marriage has permanently broken down. This breakdown can be shown in three ways: Separation for at least one year, adultery, or mental or physical cruelty that makes continuing the marriage impossible.