Change password frontend WP function

function.php

function change_pass_frontend() {
    require_once( ABSPATH . 'wp-includes/class-phpass.php');
    $old_pass = $_POST['old_pass'];
    $new_pass = $_POST['new_pass'];
    $user_id = $_POST['user_id'];
    $user_data = get_userdata( $user_id );
    $wp_hasher = new PasswordHash(8, TRUE);
    $password_hashed = $user_data->user_pass;
    if($wp_hasher->CheckPassword($old_pass, $password_hashed)) {
        wp_set_password( $new_pass, $user_id );
        die('Your password is changed succssfully');
    } else {
        die('Your old password did not match');
    }

}