How do I update an existing document inside ElasticSearch index using NEST?

I have successfully updated existing items in my Elasticsearch index with NEST using a method like the following. Note in this example, you only need to send a partial document with the fields that you wish to be updated.

    // Create partial document with a dynamic
    dynamic updateDoc = new System.Dynamic.ExpandoObject();
    updateDoc.Title = "My new title";

    var response = client.Update<ElasticsearchDocument, object>(u => u
        .Index("movies")
        .Id(doc.Id)
        .Document(updateDoc)
     );

You can find more examples of ways to send updates in the NEST Update Unit Tests from the GitHub Source.