Uncle not wiling to divide property as per Will of grandfather

registered will of grandpa has given2 nos of plots share of property to my father which has a plot in between in name of dead uncle who has no successor .we want to sell our both plots property along with half share of dead uncles property,third uncles family not coopoerating for dividation of property as per will. what to do so that w get our share in our name and can sell it