From OriginsRO wiki
OverviewIn Aldebaran, talk to the Civil Registry Clerk , he is located within Kafra Headquarters, in northwest Aldebaran.
1. You will have to pay 500,000z.
2. You will receive a.
3. Use that ticket as if it were any item.
4. Go to the character-selection screen.
5. Right-click the character and click Rename.