can the legal trustee of a revocable living trust change a trust?

The settlor (also called the trustor) is the person who creates a revocable trust.  Usually, the same person is the trustee. The settlor can change a trust that is revocable. If the settlor is also the trustee, the settlor changes the trust in their capacity as the settlor. If the trustee is not the same person as the settlor, then the trustee will only have the powers given in the trust instrument.  If the trust gives the power to change the trust, then the trustee can change the trust.