WordPress – WooCommerce Delete all products from cart and add current product to cart

To explain each do_action is inside the woocommerce-hooks.php and points to a Function inside of woocommerce-template.php

Creates thumbnail:

Function Name: woocommerce_template_loop_product_thumbnail()

do_action( 'woocommerce_before_shop_loop_item_title' );

Provides Price:

Function Name: woocommerce_template_loop_price()

do_action( 'woocommerce_after_shop_loop_item_title' );

Add to Cart Button:

Function Name: woocommerce_template_loop_add_to_cart()

do_action( 'woocommerce_after_shop_loop_item' );

Replace your external.php file with the following code.

<?php
/**
 * External product add to cart
  *
  * @author         WooThemes
  * @package    WooCommerce/Templates
  * @version     2.1.0
  */

 if ( ! defined( 'ABSPATH' ) ) {
 exit; // Exit if accessed directly
 }

 global $product;
 ?>

 <?php do_action( 'woocommerce_before_add_to_cart_button' ); ?>

  <p class="cart">
  <a href="<?php echo esc_url( $product_url ); ?>" rel="nofollow" class="single_add_to_cart_button button alt"><?php echo $product->get_price_html(); ?>
<?php echo $button_text; ?>
</a>
</p>

<?php do_action( 'woocommerce_after_add_to_cart_button' ); ?>