Nothing provided in this title prevents the release of a portion of any mortgaged interest in real property from the lien of the mortgage by any instrument in writing duly executed in the presence of one or more witnesses and duly probated, the release to be executed by the owner or holder of the lien or his duly authorized representative as will appear by the record of the original instrument or of any assignment thereof. If the release is written upon or attached to the original mortgage no probate thereof is required.
S.C. Code § 29-3-470