The Admin bar is a special container composed of portlets and defined in WEB-INF/conf/portal/portal/sharedlayout.xml.

If you want to redefine these portlets, you need to override this file by creating your own sharedlayout.xml located into your extension: custom-extension.war!WEB-INF/conf/portal/portal/sharedlayout.xml.

Followings are two examples of configuration, one to remove a portlet, the other to add a new portlet to the Admin bar.