.NET Fiddle

CSharp · Console

/Program.cs

using System;
using System.Xml.Linq;
using System.Linq;
using System.Text;
using System.Threading;
using System.Xml.Serialization;
using System.Xml.XPath;
public class Program
{
	public static void Main()
	{
		
        var xml = XDocument.Parse("<Container xmlns:i=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns=\"DM\"><IsConsigned>false</IsConsigned><LockState>Unlocked</LockState><SourceType i:nil=\"true\" /><Id>04216194-4f62-47ee-ab21-c1053d01bf1e</Id><Owner>IN</Owner><Created>2012-08-21T09:29:10.528321+02:00</Created></Container>");
        XElement xmlElement = xml.Root;
		foreach(var e in xmlElement.DescendantsAndSelf())
		{
            
                if (e.Name.Namespace != XNamespace.None)
                {
                    e.Name = XNamespace.None.GetName(e.Name.LocalName);
                }
                if (e.Attributes().Any(a => a.IsNamespaceDeclaration || a.Name.Namespace != XNamespace.None))
                {
                    e.ReplaceAttributes(e.Attributes().Select(a => a.IsNamespaceDeclaration ? null : a.Name.Namespace != XNamespace.None ? new XAttribute(XNamespace.None.GetName(a.Name.LocalName), a.Value) : a));
                }
            
		}
        string test1 = xml.XPathSelectElement("/Container/Owner").Value.ToString();
		Console.WriteLine(test1);
        string test = xmlElement.Element("Owner").Value.ToString();
	}
}