Can you share sample code updating Azure configuration file using Change Deployment Configuration

Question

So I'm reading the Change Deployment Configuration on MSDN and I want to use it. I have what I think are all the components

• Formatted URI
• Uploaded a management key
• I have a modified ServiceConfiguration file

Based on the information I'm not sure how to

1. Extract my public key from the certificate I uploaded
2. Construct my response body by combining my config file and the format of the body as shown in the documentation

3. Actually submit the response with all these elements property attached.

   string myURI = "https://management.core.windows.net/MySubscriptionID/services/hostedservices/MyServiceName/deploymentslots/staging/";
   string myManagementCertificationPublicKey = "keyvalue";
   string myNewConfigFile = "Loaded and modified xDocument";