You need to edit the template.php in your drupal theme.
Add the following.
function _phptemplate_variables($hook, $vars = array() )
{
$css = drupal_add_css();
unset($css['all']['module']);
unset($css['all']['module'][drupal_get_path('module','cck').'/date.css']);//xtra example
unset($css['all']['module'][drupal_get_path('module','cck').'/fieldgroup.css']);//xtra example
$css['all']['module']['modules/thickbox/thickbox.css'] = 1;
$vars['styles'] = drupal_get_css($css);
$js = drupal_add_js();
unset($js['module']['modules/thickbox/thickbox.js']);
$vars['scripts'] = drupal_get_js('header', $js);
return $vars;
}