Of the 2 general ideas put forward

You can go to any QF office and get it done, however you will (a) be charged AUD75 service fee plus (b) charged fuel surcharges at the QF levels as well as the normal USD125 fee plus any additional taxes

If you phone the AA ATW desk, you can get the ticket changed and set up for reissue; you will be able to find out whether it can be issued as an eticket at that time; post the paper ticket to the AA ticket office and they will take the USD125 plus new taxes from your credit card plus reisusse the ticket and ( if a paper ticket ) post the new ticket to you

If you are not in a rush and do not need it urgently then I would suggest getting AA to do it

Dave