Replace an Element

 
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;

class Program
{
    static void Main()
    {
        XElement items = XElement.Parse("<items><one/><two/><three/></items>");
        items.FirstNode.ReplaceWith(new XComment("One was here"));

        Console.WriteLine(items);
    }
}