IN SERVICE TAX UNDER A PARTNER SHIP FIRM IF A AUTHORISED SIGNATORY (PARTNER)IS RETIRE AND NEW PARTNER IS JOINING AFTER EXECUTING THE RECONSTITUTION DEED THEN WHAT IS THE PROCEEDURE FOR CHANGE OF SIGNATORY IN SERVICE TAX DEPT. ( I.E. IN ST-2 FORM ) OR CHANGE IN PAN NO. AND ALSO WHAT IS THE IMPORTANT DOCUMENT TO BE SUBMITTED TO EFFECT THE ABOVE CHANGE.