Acessing & modifying config items from library

[eluser]AlexDSX[/eluser]
Got my solution.

Code:

public function css($name = '', $path = '')
  {
   $this->CI =& get_instance();
   $template = $this->CI->config->item('template');
   $template['css'][$name] = $path;
   $this->CI->config->set_item('template', $template);
  }

It needs work but it's an example if anyone else has the same question.