How do I get the - "check form changer" plugin to use its own css

Hi,

I'm trying to get the "check form changer" to work properly. It appears when I look at in chrome that it is using the .css from the theme and not the plugin.

http://webfx.cz/store/products/pro-sites-custom-checkout/

Does anyone know how to force the plugin to use its own cfc.css?

@aristath

Thanks,
Chris