adopted a child

Asslam U Alikum! My Brother adopted a child of his Brother-in-law. And in ID card of that child,My brother instead of entering the real father s` of that child,entered his own name as his father. Now my brother is dead. That adopted child is becoming partener in the property which is to be distributed among us. That is against the rules of ISLAM. Now I want to remove my brother name from id card of that child and enter the true father name of that child. IS IT POSSIBLE? IF YES? THE TELL HOW? OR TELL TIME WHEN WE CALL TO YOU?