Removing Killed Session from the Database.

 Hi
How to remove oracle session with status as Killed, and don't have a OS process id Assosciated with it.?

SQL> select sid,serial#,status from v$session where  status='KILLED';

       SID    SERIAL# STATUS
---------- ---------- --------
        32      48013 KILLED
        75      55208 KILLED
        84      60588 KILLED
        87      63907 KILLED
       107      23406 KILLED
       108      65093 KILLED

SQL> select sid,serial#,STATUS from v$session where paddr not in (select addr from v$process)
and username is not null;
  2    3
       SID    SERIAL# STATUS
---------- ---------- --------
        32      48013 KILLED
        75      55208 KILLED
        84      60588 KILLED
        87      63907 KILLED
       107      23406 KILLED
       108      65093 KILLED