One of the beneficiary is blackmailing other beneficiary as well as will executor to give an undertaking which says, the executor will not construct anything on roof without other beneficiary's consent. But father:'s will has granted the roof to the executor cum beneficiary... Other beneficiary blackmailed him saying she won't give consent petition if her elder brother cum executor doesn't give such undertaking..she also influenced the witnesses of the will not to appear before court as witnesses if her elder brother doesn't agree to such terms. Witnesses are blackmailing the executor cum elder brother.
What legal steps can be taken against such blackmail?
Can he withdraw or revoke the undertaking once will probate is completed as such undertaking is contradictory to what father has written in his last testament?