Just set the Stop publish date to a date that has passed.

Thanks for the reply Erik, I tried using Stop publish date but must be doing something wrong. I tried not using the Instance in the PageDataCollection but it does not work either. I get this error message from the server "The property PageStopPublish is read-only."

public static PageReference parent = new PageReference(10);

public PageDataCollection pageCollection = DataFactory.Instance.GetChildren(parent);


public void unpublishOldPages()
{
  foreach (PageData p in pageCollection)
  {
    if (//Some code)
    {
       p.StopPublish = DateTime.Now;
    }
  }
}

You need to create a writable clone of the pagedata object, and then of course save it.

in the foreach

PageData writablePage = p.CreateWrtableClone();

writablePage.StopPublish = DateTime.Now;

Datafactory.Instance.Save(writablePage, yourparams...);

It worked perfect. Thanks Erik