code: public void removeFromSession( HttpServletRequest request )
      {
          StorageHandler sh = Handlers.get( getServletContext() ).getStorageHandler();
          HttpServletRequest unwrappedRequest = PageFlowUtils.unwrapMultipart( request );
          RequestContext rc = new RequestContext( unwrappedRequest, null );
          String attrName =
                  ScopedServletUtils.getScopedSessionAttrName( InternalConstants.FACES_BACKING_ATTR, unwrappedRequest );
          
          sh.removeAttribute( rc, attrName );
      }
docs: Remove this instance from the session.