change the div attributes only, not the content?

[Brill Pappin]

How can I change *only* the div attributes (like style class) without
changing the contents of the div?
 
in this example:
<div class="aaa" wicket:id="outter>
    <div wicket:id="inner">this should remain</div>
</div>
 
I want to change the css class from aaa to bbb, but not replace the inner
html.
 
- Brill Pappin