The tutorial explain on how to remove the powered by Jcal 1.5 footer information in your Jcal Pro joomla component.
Here’s how:
1. Back up joomlaroot/components/com_jcalpro folder
2. Removed he following lines
themes/default/theme.php , lines 1237-1239:
<div class="atomic">Powered by <a
href="http://dev.anything-digital.com/" target="_blank"><strong>JCal
Pro <span style="color: orange">1.5</span></strong></a></div>

include/functions.inc.php, lines 1350-1356:
$signature = ‘<a href="http://dev.anything-digital.com/" target="_blank">JCal Pro Calendar <span style="color:#FFA500"> ‘ . CALENDAR_VERSION . [...]