If you need to change the default set of product tabs displayed on the product details page in the storefront, use the Custom product tabs add-on.
With this add-on, you can specify which of the standard X-Cart store tabs should be displayed on the product page and in what order. If you need more tabs, you will also be able to add custom tabs of your own.
To start using the add-on, install it as described in Installing Add-ons from X-Cart App Store. When enabled, the add-on adds the "Product tabs" page to the store's Admin area, where you can create new and manage existing global and product-specific product tabs.