Let me start by saying that I'll be releasing a Patron-only beta for the rewrite today and it's going to completely refresh and enrich the entire game to make it easier to move forward in every single direction I want to.
That being said, if you don't want to get on it, you update the game simply by downloading the latest version, unpacking it in it's own folder and play. The saves should be stored in some other folder that's shared between everything installed on your PC and be recognized automatically.