According to Probate Code section 15402, it is possible to amend a trust according to the terms of the trust. If the terms of the trust are silent on the issue of an amendment, then the procedure set out in the Probate Code section 15402 should be used. Probate Code section 15402 stipulates that writing signed by a settlor and delivered to a trustee is required to amend a trust. What is settlor? A settlor is a person who makes or signs the trust. A settlor is also referred to as a trustor or grantor. However, in most cases, the.