Although we did not recommend removing the copyright from the footer, most of us need to do it, so we'll show you how to remove the copyright from the footer. Go to
footer.tpl, and find the following lines of code:
<p><?php echo $powered; ?></p>
Remove this code and the copyright will removed. Now, you can place your own copyright sentences.
Although not recommended, another way is to go to
catalog/language/english/common/footer.php and find the following line:
$_['text_powered'] = 'Powered By <a href="http://www.opencart.com">OpenCart</a><br /> %s © %s';
Change this text as per your requirements. You need to know that the first
%s sign shows ...