I think i might know the answer to that. I think it was in the faq section that they said you would just download an updater for it, then update it from that. Check in the faq.
Yea it says \"TO play the game you will need to download a client for your OS (Windows, Linux, etcc...). This client will be for the first demo only about 30-40 Mb. It will increase in size in later releases, but we will provide an auto-update program that will downlaod necessary software when you start the game.\"