I'm a very new programmer but I suspect you'd need to have your game do a version check with an online file (you could simply have it compare if the version number it has is smaller than a string in a file on a web server somewhere. IE: internal version = 22.214.171.124 VS file on web server = 126.96.36.199
Once you have that point (the easy part) you'd then want to retrieve a file that contains the updates and download it to an appropriate location.
Then, the game would need to take that data and incorporate it into itself. That would be interesting. I'm guessing the game would need a restart?
I'd love to watch this thread and see if someone with real skills has an answer on how to do that. Good luck!