Reset INTERNAL password in APEX 3.0

$ sqlplus /nolog
SQL> conn / as sysdba
SQL> alter user APEX_030200 identified by passwd account unlock;
SQL> conn APEX_030200/passwd
SQL> begin
    wwv_flow_api.set_security_group_id (p_security_group_id => 10);
    wwv_flow_fnd_user_api.create_fnd_user(
        p_user_name => 'admin',
        p_email_address => 'rewrygouveia@gmail.com',
        p_web_password => 'admin');
end;
/
SQL> commit;
SQL> conn / as sysdba
SQL> alter user APEX_030200 account lock;

PS: E não se esqueçam de que, a Workspace default é "internal".
Querem saber mais sobre APEX, consulte http://www.apex-blog.com/oracle-apex/installing-apex-tutorial-23.html.