This tutorial is going to show you how to change the footer copyright in Joomla 2.5 template.
<p class="copyright"><?php echo $sitename. ' © '. date('Y') . $this->get('text'); ?> | <a href="index.php/contacts"><?php echo JText::_('TPL_PRIVACY'); ?></a></p>
3) In order to change the text that says Joomla, open the configuration.php file in the root (e.g. public_html, httpdocs, www etc) folder and change it where it says:
public $sitename = 'Joomla';
Feel free to check the detailed video tutorial below:How to change footer copyright in Joomla 2.5 template,