Since the theme is hosted on the official WordPress website all updates get automatically on your page interface in WordPress admin.

If an update to the newer version is available, WordPress will notify you in the Dashboard - Updates section, where by clicking on the theme checkbox and then clicking Update Themes, you will install the latest available version of the theme.

You can also get a theme update in the Appearance - Themes section to see that a newer version of the template is available.

Just click on the Update now link to get an immediate update.