UPDATE APPLE ID SETTINGS

WHEN I GO TO DO THIS IT ASKED FOR THE OLD PASSWORD AND I DON'T KNOW IT . THAT IS WHY I HAD TO RESTORE MY PHONE AND IN THE PROCESS I LOST ALL MY CONTACTS AND GAMES.THEN IT SAYS APPROVE THIS IPHONE ON THE OTHER DEVICES SIGNED IN TO ICLOUND . I TRIED BUT I CANT GET IT TO WORK.