Question

How can I change the checkout page headings in Magento?

Answer 1

Of course, the simplest way is to change this headings in translation file (Mage_Checkout.csv). But if you want to use some custom labels, and you don’t want to conflict with native translations for other blocks on checkout, you should update those labels:

these classes are located in app/code/core/Mage/Checkout/Block/Onepage.

• Billing.php
• Shipping.php
• Payment.php
• Review.php

You can change label in _construct() method.
For example:

class Mage_Checkout_Block_Onepage_Review extends Mage_Checkout_Block_Onepage_Abstract
{
    protected function _construct()
    {
        $this->getCheckout()->setStepData('review', array(
            'label'     => Mage::helper('checkout')->__('Order Review'), // your custom label here
            'is_show'   => $this->isShow()
        ));
        parent::_construct();

        $this->getQuote()->collectTotals()->save();
    }
}

You can override those classes.