Make thumbnails replace the main image instead of opening fancybox [wooCommerce]

nice_woocommerce_gallery.php

<?php
/**
 * Plugin Name: nice_woocommerce_gallery 
 *
 */



add_action('wp_footer','nice_woocommerce_gallery');
function nice_woocommerce_gallery() {
?>

<script>
 jQuery(document).ready(function($){

 	 
 	$(document).on('click','.thumbnails a',function(e){

   		e.preventDefault();
   		var img_url = $(this).attr('href');
   		var img_src = $(this).find('img').attr('srcset');
 		$('.woocommerce-main-image').find('img').attr('src',img_url);
 		$('.woocommerce-main-image').find('img').attr('srcset',img_src);
 		$('.woocommerce-main-image').closest('a').attr('href',img_url);

 		$("a.zoom").prettyPhoto({
			hook: 'data-rel',
			social_tools: false,
			theme: 'pp_woocommerce',
			horizontal_padding: 20,
			opacity: 0.8,
			deeplinking: false
		});
		$("a[data-rel^='prettyPhoto']").prettyPhoto({
			hook: 'data-rel',
			social_tools: false,
			theme: 'pp_woocommerce',
			horizontal_padding: 20,
			opacity: 0.8,
			deeplinking: false
		});

 	});
 });
</script>

<?php 
}

if(!function_exists('woocommerce_show_product_thumbnails')) {
	function woocommerce_show_product_thumbnails() {
		global $post, $product, $woocommerce;
		$attachment_ids = $product->get_gallery_attachment_ids();
		if ( $attachment_ids ) {
			$loop 		= 0;
			$columns 	= apply_filters( 'woocommerce_product_thumbnails_columns', 3 );
			?>
			<div class="thumbnails <?php echo 'columns-' . $columns; ?>"><?php
				foreach ( $attachment_ids as $attachment_id ) {
					$classes = array( 'thumbnail' );
					if ( $loop === 0 || $loop % $columns === 0 )
						$classes[] = 'first';
					if ( ( $loop + 1 ) % $columns === 0 )
						$classes[] = 'last';
					$image_link = wp_get_attachment_url( $attachment_id );
					if ( ! $image_link )
						continue;
					$image_title 	= esc_attr( get_the_title( $attachment_id ) );
					$image_caption 	= esc_attr( get_post_field( 'post_excerpt', $attachment_id ) );
					$image       = wp_get_attachment_image( $attachment_id, apply_filters( 'single_product_small_thumbnail_size', 'shop_thumbnail' ), 0, $attr = array(
						'title'	=> $image_title,
						'alt'	=> $image_title
						) );
					$image_class = esc_attr( implode( ' ', $classes ) );
					echo apply_filters( 'woocommerce_single_product_image_thumbnail_html', sprintf( '<a href="%s" class="%s" title="%s" >%s</a>', $image_link, $image_class, $image_caption, $image ), $attachment_id, $post->ID, $image_class );
					$loop++;
				}
			?></div>
			<?php
		}
	}
}