A. If you want to revoke Power of Attorney, you can issue a legal notice to the holder by highlighting revocation of all the powers which was conferred by you.
B. You need to publish the same in the Local News paper to bring notice to the Public to prevent abuse of power.
C. In case, if the General Power of Attorney was registered, both parties should cancel the same before the Sub Registrar Office. Before executing the same, you can issue a legal notice to the attorney holder.