How to remove review step in checkout

Observer.php

	public function saveOrder($observer)
	{
	    /** @var $controllerAction Mage_Checkout_OnepageController */
	    $controllerAction = $observer->getEvent()->getControllerAction();
	    /** @var $response Mage_Core_Controller_Response_Http */
	    $response = $controllerAction->getResponse();

	    /**
	     * jsonDecode is used because the response of the XHR calls of onepage checkout is always formatted as a json
	     * string. jesonEncode is used after the response is manipulated.
	     */
	    $paymentResponse = Mage::helper('core')->jsonDecode($response->getBody());
	    if (!isset($paymentResponse['error']) || !$paymentResponse['error']) {
	        /**
	         * If there were no payment errors, immediately forward to saving the order as if the user had confirmed it
	         * on the review page.
	         */
	        $controllerAction->getRequest()->setParam('form_key', Mage::getSingleton('core/session')->getFormKey());

	        /**
	         * Implicitly agree with the terms and conditions by confirming the order
	         */
	        $controllerAction->getRequest()->setPost('agreement', array_flip(Mage::helper('checkout')->getRequiredAgreementIds()));

	        $controllerAction->saveOrderAction();
	        /**
	         * jsonDecode is used because the response of the XHR calls of onepage checkout is always formatted as a json
	         * string. jesonEncode is used after the response is manipulated.
	         *
	         * $response has here become the response of the saveOrderAction()
	         */
	        $orderResponse = Mage::helper('core')->jsonDecode($response->getBody());
	        if ($orderResponse['error'] === false && $orderResponse['success'] === true) {
	            /**
	             * Check for redirects here. If there are redirects than a module such as Adyen wants to redirect to a
	             * payment page instead of the success page after saving the order.
	             */
	            if (!isset($orderResponse['redirect']) || !$orderResponse['redirect']) {
	                $orderResponse['redirect'] = Mage::getUrl('*/*/success');
	            }
	            $controllerAction->getResponse()->setBody(Mage::helper('core')->jsonEncode($orderResponse));
       		}
    	}
	}

Onepage.php

class [Company]_[NameModule]_Block_Checkout_Onepage extends Mage_Checkout_Block_Onepage
{
	protected function _getStepCodes()
	{
	    if ($this->getQuote()->isVirtual()) {
	        return array('login', 'billing', 'payment');
	    }
	    return array('login', 'billing', 'shipping', 'shipping_method', 'payment');
	}
}