If you don't want any kind of complication or confusion then make changes with Virgin Australia Change Flight. Virgin change flight states that passengers can change their flight bookings for absolutely free within 24 hours and without paying any fee. For the modifications in the ticket, you will need to pay some charges if you missed out on the free change window. And also, passengers have to pay the fare difference in the old and new flight ticket. https://airlinespolicy.com/flight-change-policy/virgin-australia-flight-change-policy/