I look where you suggested, is this the correct part:
The use of Open Sans by default is localized. For languages that use
* characters not supported by the font, the font can be disabled.
*
* To disable in a child theme, use wp_dequeue_style()
* function mytheme_dequeue_fonts() {
* wp_dequeue_style( ‘twentytwelve-fonts’ );
* }
* add_action( ‘wp_enqueue_scripts’, ‘mytheme_dequeue_fonts’, 11 );
*/
