In your father's will he distrubuted his property to all of you, except his second son, who was disinherited from his property. He is death and all of you want to share equally of your father's property.
Ans-
Since your father is death you can not make a Codicil.
All the legatees desire for sharing equally of your deceased father's property.By all means, there is no earthly reasons why it can not be done..
No need to cancel the will. If your father is not having any debt etc, just share it equally including the second son, as your father will not reserucate from his death to object it.