I'm in the middle of helping my mother transfer my father's Delta SkyMiles account to hers. They require (1)a form supplied by them, (2)a copy of the death certificate, (3)a copy of the court order designating her as executrix of Dad's estate, and (4)an affidavit specifying what to do with the miles. (She could split the miles up between anybody she designated by showing Skymiles account number and number of miles to be designated for that account.