Eviction of my uncle from my grand father's house.

My grandfather has devided his native house property between my father and grandfather verbally. My uncle built a house in half of the plot and the other half is having our old house. My family with my grandfather moved to city 10 years back, and my uncle and his sons used to stay in that whole property. We allowed them to use my father's share as well. Now when my father is asking to vacate my father's half share of that property (old house), he is not willing to do so. The whole property is still on my grandfather's name and he's ready to help my father in every possible way to get back our share. My grandfather requested my uncle several times, but he is threatening my grandfather and my father. Can you please help me out what legal action we can take? My grandfather is willing to register the whole property (both my uncle and father's share) to my name but I don't want the uncle's part, we only want our share. However, as he is in procession of the whole property it would be hardly matter for him if we transfer only the father's share of the property to my name and file eviction suit, he will continue using the whole property as it is. My intention is to somehow legally pressurise him so that he returns back my father's share and that's why I'm thinking of registering both the share of the property to my name and file a eviction. Please suggest what should we do to return back my father's share.