Magento 1.9 remove item from Checkout Page

I’m trying to remove an item from the cart, but I need to remove it on the payment page (checkout)

I’m using the following code

$cartHelper = Mage::helper('checkout/cart');
$cartItemId = 651;
$cartHelper->getCart()->removeItem($cartItemId)->save();

but the product is not removed, am I doing it wrong? I saw that there is a URL to delete the item from the checkout page
checkout/cart/delete/id/

but I don’t know how to execute this, as soon as I load the page, can anyone help me?