These comments are made for educational purposes only and do not constitute legal advice. No attorney-client relationship exists between us.
You need 2 affidavits of heirship which declares your father’s death, names his spouses and children, names the witness’ relationship to your father, and the assets of the estate. Once the originals are signed and notarized, file them with the county clerk property records. These then need to be given to the bank. This is just a rough outline. You need an attorney to give a proper document.