How to change WooCommerce error messages

Easiest way would be with a custom translation.

https://docs.woothemes.com/document/woocommerce-localization/

And when I update the WooCommerce plugin or any themes, my text changes will remain intact? That’s really what I’m concerned about.

Is editing functions.php in the child theme and using add_filter() the best way to customize text where that’s possible? (error messages don’t seem to be set up that way)