Sort comments in wordpress without using plugins

Hi, In my word press blog; I would like to add a sort option for comment in every post without using a plugin.I am using wp_list_comments() for dump all comments.This is because I would like to enable threaded comments. I saw some tutorials with array_reverse($comments) which is working with foreach($comments as $comment).Is there any simple way to implement a sort option by older first and reverse within wp_list_comments() or Is it possible to implement threaded(reply for every comments) option with foreach($comments as $comment).Help me please…Thanks