Legal Question in Wills and Trusts in California

You need to speak with a probate attorney. Trusts have "trustees"; estates have executors or administrators. Letters testamentary are obtained through a probate proceeding in court when the decedent (deceased person) had a will. The court appoints the person who receives the "letters".

If the bank account balance is no more than $150,000, you might be able to submit a Probate Code 13100 "small estate" declaration in lieu of (expensive, lengthy) probate with Letters Testamentary. But you should talk to an attorney (bring a list of all trust and n on-trust assets) to find out if your situation is eligible for that.