S.C. Code Ann. § 44-43-345
(B) Subject to subsection (C), an anatomical gift by a person authorized under Section 44-43-340 may be amended or revoked orally or in a record by any member of a prior class who is reasonably available. If more than one member of the prior class is reasonably available, the gift made by a person authorized under Section 44-43-340 may be: