Hi,
That change should be done inside a child theme so we don’t have this problem when a new update comes.
Regarding the translation you should add the code below to your functions.php of the child theme, and copy the translation files to the the folder “languages” inside the child theme files. That director doesn’t exist by default, you need to create it.
function my_child_theme_setup() {
load_child_theme_textdomain( 'swiftframework', get_stylesheet_directory() . '/languages' );
}
add_action( 'after_setup_theme', 'my_child_theme_setup' );
-Rui