I have an XDocument that looks similar to

<root>
     <a>
          <b foo="1" bar="2" />
          <b foo="3" bar="4" />
          <b foo="5" bar="6" />
          <b foo="7" bar="8" />
          <b foo="9" bar="10" />
     </a>
</root>

I wish to change the attribute foo to something else, and the attribute bar to something else. How can I easily do this? My current version (below) stack overflows with large documents, and has an awful smell to it.

        string dd=LoadedXDocument.ToString();
        foreach (var s in AttributeReplacements)
            dd = dd.Replace(s.Old+"=", s.New+"=");