1 Open the 'content/*theme*/footer.tpl.php' file and add the following before the closing body tag:
<?php
echo $this->SEC_TOKEN;
?>
2 Open the following files:
content/*theme*/create.tpl.php
content/*theme*/login.tpl.php
Add in the captcha option (refer to new files)
<?php
echo $this->CAPTCHA;
?>