woo-change-addtocart-link.php

<?php
//* Change the Add To Cart Link
add_filter( 'woocommerce_loop_add_to_cart_link', 'sfws_add_product_link' );
function sfws_add_product_link( $link ) {
	global $product;
	$product_id = $product->id;
	$product_sku = $product->get_sku();
	$link = '<a href="'.get_permalink().'" rel="nofollow" data-product_id="'.$product_id.'" data-product_sku="'.$product_sku.'" data-quantity="1" class="button add_to_cart_button product_type_variable">'.sfws_woocommerce_product_add_to_cart_text().'</a>';
	return $link;
}
 

woo-text-change.php

<?php

//* Change Add To Cart to Select Options
//add_filter( 'woocommerce_product_add_to_cart_text' , 'sfws_woocommerce_product_add_to_cart_text' );

function sfws_woocommerce_product_add_to_cart_text() {
	global $product;
	
	$product_type = $product->product_type;
	
	switch ( $product_type ) {
		case 'external':
			return __( 'Buy product', 'woocommerce' );
		break;
		case 'grouped':
			return __( 'View products', 'woocommerce' );
		break;
		case 'simple':
			return __( 'Select Options', 'woocommerce' );
		break;
		case 'variable':
			return __( 'Select options', 'woocommerce' );
		break;
		default:
			return __( 'Read more', 'woocommerce' );
	}
	
}