Magento - Proceed to Checkout button location in theme

Open this path in your root directory:

public_html/app/design/frontend/base/default/template/checkout 

/onepage/link.phtml

Here, you can find the following code:

<?php if ($this->isPossibleOnepageCheckout()):?>
    <button type="button" title="<?php echo Mage::helper('core')->

 quoteEscape($this->__('Proceed to Checkout')) ?>
   " class="button btn-proceed-checkout ban-checkout 
<?php if ($this->isDisabled()):?> 
    no-checkout
<?php endif; ?>"
<?php if ($this->isDisabled()):?> 
     disabled="disabled"
<?php endif; ?> 
    onclick="window.location='<?php echo $this->getCheckoutUrl() ?>';">  
      <span>
        <span>
          <?php echo $this->__('Proceed to Checkout') ?>
        </span>
      </span>
  </button>
<?php endif?>