NamespaceTypeConvert.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace A
{

    public class Inner
    {
        public class InnerInner
        {
            public int Momom;
        }
    }
    public class Do
    {
        public int Bebe
        {
            get; set;
        }
        public Inner.InnerInner InnerInner;

        public int Ababa;
    }
}

namespace B
{
    public class Inner
    {
        public class InnerInner
        {
            public int Momom;
        }
    }
    public class Do
    {
        public int Bebe
        {
            get; set;
        }
        public Inner.InnerInner InnerInner;
        public int Ababa;
    }
}
namespace ConsoleApplication1
{


    class Program
    {
        static T Convert<T>(object From)  where T: class 
        {
            Type valueType = From.GetType();
            System.Xml.Serialization.XmlSerializer xmlSerializer =
              new System.Xml.Serialization.XmlSerializer(valueType);

            StringBuilder stringBuilder = new StringBuilder();

            System.IO.StringWriter stringWriter = new System.IO.StringWriter(stringBuilder);

            xmlSerializer.Serialize(stringWriter, From);

            string soapSerializedValueObject = stringBuilder.ToString();

            System.Xml.XmlTextReader xmlTextReader =
              new System.Xml.XmlTextReader(new System.IO.StringReader(soapSerializedValueObject));
            System.Xml.Serialization.XmlSerializer mySerializer = new
              System.Xml.Serialization.XmlSerializer
              (typeof(T));

            object newValueObject = mySerializer.Deserialize(xmlTextReader);
            return newValueObject as T;
        }

        static void Main(string[] args)
        {
            var before = new A.Do();
            before.Ababa = 55;
            before.Bebe = 44;
            before.InnerInner = new A.Inner.InnerInner();
                before.InnerInner.Momom = 356;
            Console.WriteLine(before.Ababa + " " + before.Bebe + " " + before.InnerInner.Momom);
            var after = Convert<B.Do>(before);
            Console.WriteLine(after.Ababa + " " + after.Bebe + " " + after.InnerInner.Momom);
        }
    }
}