get the locked objects:
SELECT s.sid,
s.serial#,
l.lock_type,
l.mode_held,
l.mode_requested,
l.lock_id1
FROM dba_lock_internal l,
v$session s
WHERE s.sid = l.session_id
AND UPPER(l.lock_id1) LIKE '%PKG_NAME%'
AND l.lock_type = 'Body Definition Lock';
Kill the sessions:
ALTER SYSTEM KILL SESSION 'sid,serial#' ;