Sister is not allowing to reach to property what can be done

Sir, my grand father ( mother's father) have only two daughter and having no son.Both daughters are married.once a day my grand father requested to both of their daughters that one of you come for residing with them .X agreed and Y refused.Then X started live with their parents for looking after them and their property also.Then my mother's father made a registered WILL.IN WHICH HE STATES THAT MY HOUSE IS GIVEN TO NAME OF X.WHERE Y WILL NOT INTERFERE OF ANY KIND AND REST OF MY PROPERTY WILL BE EQUALLY DIVDE B/W X AND Y. A Field in which house is mount that is half is in form of house and half is uncovered...so that uncovered field is divide in two part b/w X and Y..now problem is that for that uncovered field there is only single way to approach i.e X house entrance gate .NOW Y WANTS TO PATH FROM X TO REACH THEIR FIELD..BUT X REFUSES FOR THAT DUE TO REASON OF WILL IN WHICH HOUSE IS GIVEN TO HER.NOW SHE REFUSED FOR BREAKING THEIR BOUNDARY WALL.How can Y get a path from X.