using System;

using System.Xml.Linq;

​

public class Program

{

    public static void Main(string[] args)

    {

        const string xml =

            @"<query>

<selecttables>

   <field>

     <tablerscd>1014</tablerscd>

     <tablename> OEM IHS Engines</tablename>

   </field>

   <orderby>

      <columnrscd>1228</columnrscd>

      <columnrscd>1229</columnrscd>

   </orderby>

  </selecttables>

</query>";

​

        var doc = XDocument.Parse(xml);

​

        doc.Descendants("orderby").Remove();

​

        Console.WriteLine(doc);

    }

}

​

​

​