Sorry to hear that, however Cody did state how to patch (Well gave a link) http://www.blesta.com/forums/index.php?/topic/831-release-301/#entry6854
However it's your first time, do you have any backups mate?
Also what I do is upload the files to the server in a upload folder.
I then remove the routes.php from the /config/ folder to keep my admin and client area saved.
Then I go to /app/views/clients/ and rename default to default-3.0.1 that way it won't overwrite the custom theme.
Then move the files over to the public_html
Then run the /upgrade/
Hopefully this will help you in the future .