If you wish to change the bottom right legend, you have to open the file "/[FengOffice]/application/layouts/website.php", and modify (comment, change, delete) Line 124:
<div id="productSignature"><?php echo product_signature() ?></div>
For example, if you just want to "delete" the text:
<div id="productSignature"><?php //echo product_signature() ?></div>
You can also delete the line or do anything else you wish (Ex. add another legend) respecting the class "productSignature" in order to keep the same layout.
Just as a final comment, if you wish to change something else in the footer of the Web page, you'll have to "play" with lines 116-124 from the same file.