(a) If the document of gift or an executed copy thereof has been delivered to a specified donee, the donor may amend or revoke the gift by:

(1) The execution and delivery to the donee of a signed statement;

(2) An oral statement made in the presence of two persons and communicated to the donee;

(3) A statement during a terminal illness or injury, which statement is addressed to an attending physician and communicated to the donee; or

(4) A signed card or document found on his person or in his effects.

(b) Any document of gift which has not been delivered to the donee may be revoked by the donor in the manner set out in subsection (a) of this Code section or by the destruction, cancellation, or mutilation of the document and all executed copies thereof.

(c) Any gift made by a will may also be amended or revoked in the manner provided for the amendment or revocation of wills or as provided in subsection (a) of this Code section.