Add this code to your child theme’s functions.php file or via a plugin that allows custom functions to be added, such as the Dessky Snippets plugin. Please don’t add custom code directly to your parent theme’s functions.php file as this will be overwritten completely when you update the theme.

Use the following snippet to rename tabs.

/**
 * Rename product data tabs
 */
add_filter( 'woocommerce_product_tabs', 'woo_rename_tabs', 98 );
function woo_rename_tabs( $tabs ) {

	$tabs['description']['title'] = __( 'More Information' );		// Rename the description tab
	$tabs['reviews']['title'] = __( 'Ratings' );				// Rename the reviews tab
	$tabs['additional_information']['title'] = __( 'Product Data' );	// Rename the additional information tab

	return $tabs;

}