This tutorial will guide you through how to change the footer text on a Shape5 theme. No mention of shape5.com is required in the footer area, and can be changed or modified as needed.
OPTION 1 - FOOTER.PHP - This is the simplest method and requires you to modify a single php file and over-write your existing file via ftp.
Designed by Shape5.com <a href="http://www.shape5.com/" title="Visit Shape5.com WordPress Theme Club" target="blank" class="footerc">WordPress Themes</a>
OPTION 2 - WIDGET - you can publish any widget to the "footer" widget position. By doing this, the footer.php file for option #1 is no longer used and a widget is called in its place.
http://www.shape5.com/documentation/WordPress/Getting-Started/How-To-Install-A-Widget-Into-WordPress