(a) When a trust deed to secure a debt or obligation does not by its terms prescribe a method for substitution, the party secured by the trust deed, or any surety indemnified by the deed, or the assignee or personal representative of any secured party or surety may, if there is a death, removal, declination, resignation, refusal or inability of the original trustee or trustees named in the instrument, substitute a trustee or trustees in his or her, or its place by a writing duly signed and acknowledged and recorded in the office of the clerk of the county commission where the real estate covered by the trust deed is situate.

(b) When a substitution is made under this section of a trustee or trustees of a trust deed securing a debt or obligation, the substitution is effected when the party secured, or a surety indemnified by the deed, or the assignee or personal representative of any such secured party or surety has deposited true copies of the notice of the substitution in the United States mail, first class postage prepaid, addressed to the last known addresses of the grantor or grantors or any other person owing the debt or obligation, and has presented the original of the notice to the clerk of the county commission in whose office the trust deed is recorded, causing the notice to be recorded and indexed in a general lien book or other appropriate book in which trust deeds or assignments of trust deeds are recorded. There shall be appended to the notice presented for recording a certificate by the party making the substitution, certifying that copies of the notice were mailed as required by this subsection and showing the date of the mailing.