modify existing class?

["LuboÅ Svoboda" <svoboda dot lubos at gmail dot com>]

Hello,
is it posible to modify existing class using kawa? For example, I
would like to remove final modifier of the class and then save .class
to the filesystem.
I've tried following code but it doesn't work for my idea:

		ClassType ct = ClassType.make("test.MyFinalClass");
		
		ct.setModifiers(Access.PUBLIC);
		
		int mod = ct.getModifiers();
		System.out.println(mod);

		byte[] classFile = ct.writeToArray();
		System.out.println(classFile);
		
		ClassTypeWriter.print(ct, System.out, 0);

There is always only empty class, my methods from test.MyFinalClass
are not there. Could someone help meM
Thanks!
Luba