Cal. Prob. Code § 16338

In a proceeding with respect to a trustee’s exercise or nonexercise of the power to make an adjustment under Section 16336, the sole remedy is to direct, deny, or revise an adjustment between principal and income. In a proceeding with respect to a trustee’s exercise or nonexercise of a power conferred by Sections 16336.4 to 16336.6, inclusive, the sole remedy is to obtain an order directing the trustee to convert the trust to a unitrust, to reconvert from a unitrust, to change the distribution percentage, or to order any administrative procedures the court determines to be necessary or helpful for the proper functioning of the trust.