Edit the template

1) Open catalog/view/theme/BurnEngine/template/common/footer.tpl

2) Find and edit this code line:

<p id="copy"><span><?php echo $tbData->theme_config['copyright']; ?></p>

Edit theme config

1) Open system/vendor/BurnEngine/themes/YOUR_THEME/config.php

2) Find and edit this code line:

'copyright' => '&copy; Copyright 2014-' . date('Y') . '. Powered by <a href="http://www.opencart.com">Open Cart</a>.</span> <br /> <a class="tb_main_color" href="">YOUR THEME</a> made by <a href="http://www.themeburn.com">ThemeBurn.com</a>'