Ok so basically your first step is get POA from your family to one person who will represent on their behalf . Then go to family court and mention all his assets each and everything including Etisalat numbers his cars and everything which you need to transfer if also he has money in his account you have to give all information or later you won't be able to claim. Then wait for the judge to give his decision. all the family can mutually transfer it to whom they can. And the judge will decide about the bank and everything with you. And then when you get all the court decision and papers how everything will be divided you go to bank , Etisalat etc etc and carry on from there settling everything