A trustee can be discharged from his trust only as follows:
(1) By the extinction of the trust;
(2) By the completion of his duties under the trust;
(3) By such means as may be prescribed by the declaration of trust;
(4) By the consent of the beneficiary, if he has capacity to contract;
(5) By the judgment of a competent tribunal in a direct proceeding for that purpose that he is of unsound mind; or
(6) By the circuit court.