It is possible, but not without going back to court and, at least in Victoria, the courts will only entertain the possibility of changing Final Orders if there is deemed a significant change to circumstances that merit alterations. There are no guidelines on what are deemed significant changes, however. Typically, changes to Final Orders would be made only if there have been repeated contraventions of the Orders by the other party. And even those can be difficult to prove in court.
I would suggest discussing with a solicitor to have them draft a letter and send it to your ex, as these things carry a little more clout than your request/wishes alone.