К примеру вот запись в куку
SetCookie("uvedoms_array[".$key."][url]",html_entity_decode($uvedom_array['url'], ENT_QUOTES, 'UTF-8'),time()+$session_timeout_uvedom);
SetCookie("uvedoms_array[".$key."][title]",html_entity_decode($uvedom_array['title'], ENT_QUOTES, 'UTF-8'),time()+$session_timeout_uvedom);
SetCookie("uvedoms_array[".$key."][description]",html_entity_decode($uvedom_array['description'], ENT_QUOTES, 'UTF-8'),time()+$session_timeout_uvedom);
Вот удаление
SetCookie("uvedoms_array[".$key."][url]","",time()-$session_timeout_uvedom, '/');
SetCookie("uvedoms_array[".$key."][title]","",time()-$session_timeout_uvedom, '/');
SetCookie("uvedoms_array[".$key."][description]","",time()-$session_timeout_uvedom, '/');