If you just need to remove the tab, look in.
include/product_tabs.php
Comment out this code around line 64:
PHP Code:
if (!empty($active_modules['Special_Offers']) && !empty($product_offers)) {
$product_tabs[] = array(
'title' => func_get_langvar_by_name('lbl_special_offers'),
'tpl' => 'modules/Special_Offers/customer/product_offers_short_list.tpl',
'anchor' => 'soffers'
);
}