Legal Question in Wills and Trusts in California

It can vary, depending on whether the fiduciary is under a trust or court appointed. Some trusts specify a removal process. A court petition can be tricky, so you really should speak with an attorney about the specific facts and circumstances in your case.

I agree. You should schedule a consultation with an attorney who specializes in trust administration and probate. Whether or not your brother should or could be removed as the fiduciary is very fact specific and requires a thorough discussion of the facts and consequences.