using System;

using System.Xml.Linq;

​

public class Program

{

    public static void Main()

    {

        const string xml = @"  

<Object type=""SignalGroup"">

    <Name>General</Name>

    <Object type=""Signal"">

        <Name>Input</Name>

        <Attribute name=""Description"">This is a public object.</Attribute>

    </Object>

    <Object type=""Signal"">

        <Name>PublicName</Name>

        <Attribute name=""ToolTitle"">Public name</Attribute>

        <Attribute name=""Description"">This is a public object.</Attribute>

    </Object>

</Object>";

​

        var doc = XDocument.Parse(xml);

​

        foreach (var name in doc.Descendants("Name"))

        {

            name.Name = "Attribute";

            name.Add(new XAttribute("name", "Name"));

        }

​

        Console.WriteLine(doc);

    }

}