lol

// Rename post tag taxonomy url

add_action( 'init', 'rename_post_tag_url' );

function rename_post_tag_url() {
    $args = array(
        'rewrite' => array( 'with_front' => false, 'slug' => '../tags' )
    );

    register_taxonomy( 'post_tag', 'post', $args );
}