How to move for partition?

My grand father made a settlement giving a certain amount of land stating that , his three daughters should cultivate the land ,out of the income they have to celebrate one day worship in a particular temple. Now the land is not fir for cultivation. It has to be used for housing only.The last daughter passed away leaving three children. I am representing the elder daughter { She is demised} The second daughter is alive. So now I and my maternal And wishes to partition the the property in three divisions,sell it and Through the money we can do the worship separately, The land is in actual possession with the third daughter's son. He refuses for the partition, What i Have to do now?