For(woocommerce plugin).How to display just the product size in review-order.php

HELLO!! For(woocommerce plugin). Can somebody please help me with this: I am trying to figure out, how to display just the product size in review-order.php?? For

example a have this script in review-order.php:

<td class="product-name">'.$_product->get_title().$woocommerce->cart->get_item_data( $values ).'</td>
<td class="product-quantity">'.$values['quantity'].'</td>
<td class="product-total">' . apply_filters( 'woocommerce_checkout_item_subtotal', $woocommerce->cart->get_product_subtotal( $_product, $values['quantity'] ), $values, $item_id ) . '</td>

and i whant to display the product size (S or M or XL) like:
<td class="product-size"> value here </td>

where can i find the corect rezult to appear??

http://wordpress.org/plugins/woocommerce-variation-details-on-page-product/