Assembly asm = Assembly.GetExecutingAssembly();
XmlDocument doc = new XmlDocument();
XmlTextReader reader = new XmlTextReader(asm.GetManifestResourceStream("MyNamespace.MyXmlFile.xml"));
doc.Load(reader);

Assembly _assembly;
   StreamReader _textStreamReader;
   _assembly = Assembly.GetExecutingAssembly();
   _textStreamReader = new StreamReader(_assembly.GetManifestResourceStream("MyNameSpace.MyXmlFile.xml"));