Remove Google fonts entirely?

We are using the plugin on a setup in China. As you are possibly aware, there’s the mighty Great Firewall to protect the people from evil things like Google fonts, thus every query gets blocked and slowing the site down up to be unusable.

Can you tell me how to remove loading fonts from fonts.googleapis inside a function.php? I have no issues with loading the webfonts locally, I just don’t really understand the PHP stuff of your plugin. Thank you very much.