Change the validation rules

validateChange.php

<?php

$user = User:create();
// Get the validation rules.
$userModel =  new User();
$rules = $userModel->validates;

// Add new
$rules['password']['skipEmpty'] = true;
$rules['confirm_password'] = array(
		'match',
		'message' => 'The passwords need to match',
		'other_field' => 'password',
		'skipEmpty' => true
);

// Validate
if ($user->validates(compact('rules')) {

}