Decrease left part and increase right part of grid

-- HikaShop version -- : 2.4.0
-- Joomla version -- : 3.4
-- PHP version -- : 5.4
-- Browser(s) name and version -- : All

Hi,

I want to decrease the width of the left part of the tabular lay out. The place where the images are placed. And increase the right part. The place where the price and add to cart button is placed. Just like on the page below.

demo.hikashop.com/index.php/en/hikashop/.../with-tabular-layout

Therefore I changed this line in show_tabular.php

<div id="hikashop_product_left_part" class="hikashop_product_left_part <?php echo HK_GRID_COL_6; ?>">

and changed the 6 to 5. I did the same for the right side but then changed the 6 to 7. Total is 12 again.

But nothing changed after I changed the code. Does anyone know what I do wrong?