Client App To Consume Web Service With Security

I need to write a simple client to access a WS. Things I can not do :

Modify the serverAdd external jars 

The client will be part of a command line call and will run as a stand alone.
 
I've been searching all day and have found hundreds of vague, overly complex examples, mostly based on SOAPHandler (which tells me I need to install server components which I cannot do). I grasp the general requirements but am having difficulty figuring out how to add the security elements to the header.
 
What do I need to do to add the username and password tokens to the header?
 
This is where I am so far.

package findingLetter;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.xml.namespace.QName;
import javax.xml.soap.MessageFactory;

[Code] ....