How to kill the session

/* Formatted on 10-Apr-12 12:42:46 PM (QP5 v5.115.810.9015) */
SELECT   c.object_name,
         b.sid,
         b.serial#,
         b.machine
  FROM   v$locked_object a, v$session b, dba_objects c
 WHERE   b.sid = a.session_id AND a.object_id = c.object_id
and object_name  like 'XXHMI%'--_INV_MAS_PKG_T_EXC%'-- ='MTL_SYSTEM_ITEMS_INTERFACE';

OBJECT_NAME,               SID,SERIAL#,MACHINE

MTL_SYSTEM_ITEMS_INTERFACE,2948,7,our12-test.bilt.com
--Solution:-

alter system kill session '2255,371' Immediate;