The personal representative of a sole or surviving trustee, or if there be more than one trustee, and one or more of them die, resign, or remove from the state, or decline to accept the trust, or refuse to act as such trustee or trustees, the remaining trustee or trustees, may execute the trust, or so much thereof as remained unexecuted at the death, removal, declination, resignation, or refusal aforesaid (whether the trust subject be real or personal property), unless the instrument creating the trust directs otherwise, or some other trustee be appointed for the purpose pursuant to the provisions of this article.