How to Rename an XmlNode and all its Children

I'm trying to figure out the best way to rename an element and all of its children. For example, I would like to prepend or append arbitrary text to distinguish the node (and its children) for use in a DataSet. The code below is in .NET. The place I'm having a problem is noted below. Is there a better way to do this, XSLT perhaps?

BTW: I have to do this in C# .NET, so DOM3 isn't an option.

private void ProcessChildren(XmlNode xnod, int Depth)
{
   if ((xnod.NodeType == XmlNodeType.Element))
   {
       // WHAT DO I DO HERE TO RENAME THE CURRENT NODE???

       // Process the children of this node
       XmlNode xnodworking;
       if (xnod.HasChildNodes)
       {
            xnodworking = xnod.FirstChild;
            while(xnodworking != null)
            {
                  ProcessChildren(xnodworking, Depth + 1);
                  xnodworking = xnodworking.NextSibling;
            }
        }
    }
}

private XmlNode RenameNodes(System.Xml.XmlNode rs_node)
{
    XmlNode xnodWorking;
    if (rs_node.HasChildNodes)
    {
        xnodWorking = rs_node.FirstChild;
        while(xnodWorking != null)
        {
            ProcessChildren(xnodWorking, 0);
            xnodWorking = xnodWorking.NextSibling;
        }
     }
     return null;
}

Thanks.