Title 7, Chapter 1, Section 814
The provisions of Code Section 7-1-813 as to rights of survivorship are determined by the form of the account at the death of a party. Once established, the terms of a multiple-party account can be changed only:
(1) By closing the account and reopening it under different terms;
(2) By presentation to the financial institution of a modification
agreement in a form satisfactory to the financial institution and
signed by all parties with a present right of withdrawal.