Prestashop 1.6 Show manufacturer description on product page

I want to show product description on product page. Is posible to change product.tpl to show it? Is necessary to develop a module or change core clases?

To show the manufacturer description on product page, the best way is to create an override to ProductController like:

class ProductController extends ProductControllerCore
{
    public function initContent(){

        $manufacturer_description = "";
        if($this->product->id_manufacturer > 0)
        {
            $manufacturer = new Manufacturer($this->product->id_manufacturer, $this->context->language->id);
            $manufacturer_description = $manufacturer->description;
        }

        $this->context->smarty->assign('manufacturer_description', $manufacturer_description);

        parent::initContent();
    }
}

Then in the product.tpl of the theme place the {$manufacturer_description} where you want it to show.

Don't forget to clear cache, and delete the file cache/class_index.php after these changes to take effect.