Strip all namespaces from XML Document in C#

XmlNamespaceStripper.cs

    public class XmlStripper
    {
        public XmlNode RemoveAllNamespaces(XmlNode documentElement)
        {
            var xmlnsPattern = "\\s+xmlns\\s*(:\\w)?\\s*=\\s*\\\"(?<url>[^\\\"]*)\\\"";
            var outerXml = documentElement.OuterXml;
            var matchCol = Regex.Matches(outerXml, xmlnsPattern);
            foreach (var match in matchCol)
                outerXml = outerXml.Replace(match.ToString(), "");

            var result = new XmlDocument();
            result.LoadXml(outerXml);

            return result;
        }

        public XmlNode Strip(XmlNode documentElement)
        {
            var namespaceManager = new XmlNamespaceManager(documentElement.OwnerDocument.NameTable);
            foreach(var nspace in namespaceManager.GetNamespacesInScope(XmlNamespaceScope.All))
            {
                namespaceManager.RemoveNamespace(nspace.Key, nspace.Value);
            }

            return documentElement;
        }
    }

XmlNamespaceStripperTests.cs

    [TestFixture]
    public class NamespaceStripperTests
    {
        [Test]
        public void Should_strip_the_namespace_from_this_goddamn_xml()
        {
            var xml = new XmlDocument();
            xml.LoadXml(@"	<track xmlns=""http://www.digiplug.com/dsc/umgistd-1_4"">
								<terms>
									<terms_of_use>
										<subscription_online_streaming>N</subscription_online_streaming>
									</terms_of_use>
								</terms>
							</track>");

            var expected = new XmlDocument();
            expected.LoadXml(@"	<track>
								<terms>
									<terms_of_use>
										<subscription_online_streaming>N</subscription_online_streaming>
									</terms_of_use>
								</terms>
							</track>");

            var result = new XmlStripper().RemoveAllNamespaces(xml.DocumentElement);
            Assert.That(result.OuterXml, Is.EqualTo(expected.OuterXml));
        }
    }