title: How to upgrade WSO2 ESB
body: <p>I'm running WSO2 ESB 4.0.3 and noticed 4.5 came out.  I've tried searching but haven't been able to find anything regarding how to upgrade to the new version without breaking files I've changed.  Anyone have any ideas or direct me to a document on how I can do this?</p>
  
  <p>Thanks,
  Jared</p>