You will be unable to obtain a court order changing the beneficiary of your late aunt's estate removing your brother as one of the estate's beneficiaries. Under the laws of all states in this country, a will speaks at the death of the person signing the instrument.Your aunt gave a gift to your brother. It is his for his use. Assuming he is dead, then his heirs under a will, or if no will, under your state's intestacy laws certain people would end up receiving his share of your aunt's estate.The executor of the estate needs to make a concerted effort to locate this "lost brother" and make contact with him assuming he is alive advising him of the need to retrieve his share of the estate.A private investigator may need to be retained to locate your brother's whereabouts if the estate's executor cannot make contact with him.Good luck.