Legal Question in Wills and Trusts in California

It would be best to use the original attorney. But, if that is not an option, you can choose to use a different attorney who can draft an amendment to the trust.

By the way, the person responsible for administering the trust is called a Trustee or Successor Trustee.

It is not necessary to use the original attorney. However, you might consider the problems managing your property that might be encountered if you no longer are the trustee while you are alive and able to make your own decisions. If it's a successor trustee you wish to change, that's a different issue.