Umm im guessing here based on education but as there is no installer I assume any update is a new build so you could just take a copy of your saved folder thats in your game directory & drag it into the newly uncompressed download you have,, Run the game & check that works with your save if it does then stick to that method...... Other way of doing it would be to uncompress the new file directly into your already existing folder so all new files over wriote the old ones.......Keep a copy of your game save just in case...