Deleting XML using a selected Xpath and a for loop

I currently have the following code:

XPathNodeIterator theNodes = theNav.Select(theXPath.ToString());

while (theNodes.MoveNext())
{
    //some attempts i though were close
    //theNodes.RemoveChild(theNodes.Current.OuterXml);
    //theNodes.Current.DeleteSelf();
}

I have set xpath to what I want to return in xml and I want to delete everything that is looped. I have tried a few ways of deleting the information but it does't like my syntax. I found an example on Microsoft support: http://support.microsoft.com/kb/317666 but I would like to use this while instead of a for each.

Any comments or questions are appreciated.