To uncomment a commented node in a XML file using C#

I have a XML file which has a node which is commented out. I have created this node using the syntax:

relTableCommentedNode = xDoc.CreateNode(XmlNodeType.Comment, "RELTABLECOMMENTED", "np");

What is the best approach to uncomment this node? Can I identify this node based on the name which I used to create the node (RELTABLECOMMENTED)?

This the commented node:

<code>
<pre> 
<!--<reltable toc="no" class="- map/reltable ">
    <relheader class="- map/relheader ">
      <relcolspec type="concept" class="- map/relcolspec ">      
    </relheader>
    <relrow class="- map/relrow ">
      <relcell class="- map/relcell ">
        <topicref href="concepts\about_cannedgoods.dita" copy-to="concepts\about_cannedgoods.dita" class="- map/topicref " xmlns:dctm="http://www.documentum.com">
        </topicref>
      </relcell>      
    </relrow>
  </reltable> -->
</pre>
</code>

To the best of my knowledge, using XmlDocument, there is no direct way to do this. You will need to do something like the following

1. Get the value of the comment node
2. Create a new XmlNode with the value from step 1
3. Delete the comment node
4. Add the new node from step 2 to the DOM tree

Here is an example with a slightly simplified version of your XML and addressing your quesion in the comments on finding the correct comment node. Note that I query for all comment nodes, obviously you can be more specific and query the portion of the document that you are interested in.

  string xml = @"
    <root>
      <!--<reltable toc='no' class='- map/reltable '>
      <relheader class='- map/relheader '>
        <relcolspec type='concept' class='- map/relcolspec '/>      
      </relheader>         
    </reltable> -->

    <!--<reltable toc='no' class='- map '>
      <relheader class='- map/relheader '>
        <relcolspec type='concept' class='- map/relcolspec '/>      
      </relheader>          
    </reltable> -->
  </root>";

  XmlDocument xdoc = new XmlDocument();
  xdoc.LoadXml(xml);

  XmlNodeList commentedNodes = xdoc.SelectNodes("//comment()");
  var commentNode = (from comment in commentedNodes.Cast<XmlNode>()
              where comment.Value.Contains("class='- map '")
              select comment).FirstOrDefault();

  if (commentNode != null)
  {
    XmlReader nodeReader = XmlReader.Create(new StringReader(commentNode.Value));
    XmlNode newNode = xdoc.ReadNode(nodeReader);
    commentNode.ParentNode.ReplaceChild(newNode, commentNode);
  }