cs-cart, how to add a new "how to use" tag into product detail page

How to add a new "how to use" tag into product detail page
(1) create file, skins\basic\customer\blocks\product_tabs\howtouse.tpl
{* $Id: description.tpl 11191 2010-11-11 11:56:01Z klerik $ *}
{** block-description:howtouse **}
{$product.howtouse|default:$product.short_description|unescape}

(2) add a language variable "howtouse" => How to Use
(3) add a howtouse field into table cs_cart.product_description table
(4) In skins\basic\admin\views\products\update.tpl
line 55 add following code
<br /> <div class="form-field"><br /> <label for="product_full_descr">How to use:</label><br /> <textarea id="product_howtouse" name="product_data[howtouse]" cols="55" rows="8" class="input-textarea-long">{$product_data.howtouse}</textarea><br /> {include file="common_templates/wysiwyg.tpl" id="product_howtouse"}<br /> </div><br />