Yes, this is known as consent modification.
1) Get authorization from the grantor/creator + all beneficiaries + all trustees to make any and all changes to the trust indenture. When a minor or unborn person is a beneficiary, consent on the beneficiary’s behalf may often be given by a parent of the minor or a lineal ancestor of the unborn beneficiary; or
2) Assign a Trust Protector with provisions that allows them to step in and exercise very specific modification powers as defined in the trust agreement.
TRUST MINUTES SAMPLE FOR CHANGE OF INDENTURE: The grantor, currently named beneficiary(ies) and all trustees unanimously agree to the following changes to the trust indenture: _____________.
NOTE: The grantor is not involved UNLESS one needs to make changes to the original trust indenture. The grantor is not involved in the passing of bylaws, having voting privileges.