title: Replacing an xml element value in c#
body: <p>Here is my xml file data</p>
  
  <pre><code>&lt;Persons&gt;
      &lt;Person&gt;
          &lt;Name&gt;john&lt;/Name&gt;
      &lt;/Person&gt;
      &lt;Employee&gt;
          &lt;Detail&gt;
              &lt;Firstname&gt;john&lt;/FirstName&gt;
          &lt;/Detail&gt;
      &lt;/Employee&gt;
      &lt;Student&gt;
          &lt;FullName&gt;john&lt;/FullName&gt;
      &lt;/Student&gt;
  &lt;/Persons&gt;
  </code></pre>
  
  <p>I want to replace "john" to "danny" in all places.</p>
  
  <p>How can I do this in c# ?</p>