Cal. PROB § 19518

An authorized fiduciary may not exercise the decanting power to modify a provision in a first trust instrument granting another person power to remove or replace the fiduciary unless any of the following occurs: (a) The person holding the power consents to the modification in a signed writing and the modification applies only to the person. (b) The person holding the power and the qualified beneficiaries of the second trust consent to the modification in a signed writing and the modification grants a substantially similar power to another person. (c) The court approves the modification and the modification grants a substantially similar power to another person.