Property Inheritance

Hi Sir/Madam, Religion: Christian Property Type: Inheritance from grand parents ( Both agricultural and non-agricultural land) My grand parents passed away intestate, and they had 4 daughters one of whom is my mother. My mother passed away too, and the remaining legal heirs of my grand parents property are { My mothers (husband, son 1, son 2, daughter), 3 remaining sisters of my mother} Issue: One of my mother's sisters has the documentation (death certificates) of our grand parents, and is unwilling to provide it to the remaining heirs despite several request. What can I do to legally force them to provide those certificates so as to further obtain title information of the property. Question 1: I was suggested to issue a Legal Notice to the Door No. and to the 3 sisters. Is this the best course of action? What's does it involve and how can i do it.? Question 2: Alternative, do you have any other suggestions to approach the matter legally. Question 3: Can the land be divided without the paperwork, if they do not comply? Regards, Mathew