title: Observable Collection replace item
body: <p>I have a <code>ObservableCollection</code>, I can add and remove item from the collection. But I can't replace an existing item in the collection. There is a way to replace an item and reflect that on my bound components. </p>
  
  <pre><code>System.Collections.Specialized.NotifyCollectionChangedAction.Replace
  </code></pre>
  
  <p>Can anyone please show me how to accomplish this?</p>