Remove part of an XML attribute

I am parsing an XML document and saving it's content to a simple database via Microsoft Lightswitch application. The XML document contains some user accounts and has the following tags:

<Data Account="i:0#.w|ab001\cn0ied32" Access="0" />
<Data Account="i:0#.w|ab001\cn0ied50" Access="0" />
<Data Account="i:0#.w|ab001\cn0ied56" Access="0" />
<Data Account="i:0#.w|ab001\cn0iit01" Access="0" />
<Data Account="i:0#.w|ab001\cn0iit05" Access="0" />

I want to save the Account without the i:0#.w| before the domain and user name. So it should result in just domain\name after processing.

Here is the my class:

public class MessageInterpreter
{
   [XmlRoot("Root", IsNullable = false)]
   [Serializable]
   public class Root
   {
       [XmlElement("Data")]
       public Data[] Data{ get; set; }

       [Serializable]
       public class Data
       {
           public Data()
           {
              //Access = false;               
           }
           [XmlIgnore]
           public String Account_Nullable { get; set; }
           [XmlAttribute]
           public String Account { get { return Account.Replace("i:0#.w|", String.Empty); } set { Account_Nullable = value; } }
           [XmlIgnore]
           public bool? Access_Nullable { get; set; }
           [XmlAttribute]
           public bool Access { get { return Access_Nullable.GetValueOrDefault(); } set { Access_Nullable = value; } }

       }
    }
    private static XmlSerializer _Serializer;
    static MessageInterpreter()
    {
        _Serializer = new XmlSerializer(typeof(Root));
    }

    public MessageInterpreter()
    {
    }

    public Root ParseMessage(String message)
    {
        if (String.IsNullOrEmpty(message))
            return null;
            using (var stream = new StringReader(message))
        {
            try
            {
                return (Root)_Serializer.Deserialize(stream);
            }
            catch (Exception)
            {
                return null;
            }

        }
    }

Now when I try to import it, I get a Stack overflow exception ... I am not sure why though. Any ideas how to make it work? Or recommendations of what to/not to use?