On petition by a trustee or beneficiary, the court may modify the administrative provisions of the trust, if, owing to circumstances not known to the settlor and not anticipated by the settlor, the continuation of the trust under its terms would defeat or substantially impair the accomplishment of the purposes of the trust. If necessary to carry out the purposes of the trust, the court may order the trustee to do acts that are not authorized or are forbidden by the trust instrument.
C2001, §633.2204
CS2005, §633A.2204