How do I get my father's share of the property from my uncle?

When my grandfather passed away, he left equal shares of the property to my father and my uncle. My father passed away so his share of the property should be split between myself, my brother and two sisters. I have my grandfather's will. How do I go about getting my share from my uncle? He is going to put up a fight and I need to know how to go about it the legal way.