i changed protfolio_item slug and i cant access portfolio items

hi blueowl
i need help about change portfolio_item slug
portflio mean referans in turkish

<?php

/*
Plugin Name: Fortuna Portfolio CPT
Plugin URI: http://themeforest.net/user/blueowlcreative
Description: This Plugin creates a Portfolio Custom Post Type for Fortuna WordPress Theme.
Version: 1.0
Author: blueowlcreative
Author URI: http://blueowlcreative.com
License: Custom
License URI: http://themeforest.net/licenses
*/

/* —————————————————– */
/* Add Portfolio Custom Post Type
/* —————————————————– */
function boc_portfolio_register() {

register_post_type(
‘portfolio’,
array(
‘labels’ => array(
‘name’ => ‘Portfolio’,
‘singular_name’ => ‘Portfolio’
),
‘public’ => true,
‘has_archive’ => true,
‘rewrite’ => array(‘slug’ => ‘referanslar’),
‘supports’ => array(‘title’, ‘editor’, ‘thumbnail’),
‘can_export’ => true,
‘show_in_nav_menus’ => true,
)
);

register_taxonomy(‘portfolio_category’, ‘portfolio’, array(‘hierarchical’ => true, ‘label’ => ‘Portfolio Categories’, ‘query_var’ => true, ‘rewrite’ => true));

// Remove post_format URL param so we can use PREVIEW on portfolio items
function remove_post_format_parameter( $url ) {
$url = remove_query_arg( ‘post_format’, $url );
return $url;
}
add_filter( ‘preview_post_link’, ‘remove_post_format_parameter’, 9999 );
}
add_action(‘init’, ‘boc_portfolio_register’, 1);

// Register the Custom Templates for the Custom Post Type Portfolio
function boc_cpt_post_types( $post_types ) {
$post_types = array();
$post_types[] = ‘portfolio’;
return $post_types;
}
add_filter( ‘cpt_post_types’, ‘boc_cpt_post_types’ );

/* —————————————————– */
/* EOF
/* —————————————————– */

i changed just portfolio_item to referanslar
can u help me?

http://www.ebrarcamihalilari.com/referanslar/brand-creation-project/