We currently don't have this as an option in SCLogin, but I've added this to our issue tracker as a feature for a future release.
The easiest way that I can think to do this is with styling and a template override.
Here is a sample of CSS to add to your SCLogin theme CSS:
.sclogin .submitLink {
background-color: transparent;
text-decoration: underline;
border: none;
color: blue;
cursor: pointer;
}
Copy the /modules/mod_sclogin/tmpl/logout.php to /templates/YOUR_TEMPLATE/html/mod_sclogin directory. Then around line 35, you will see the following line:
<input type="submit" name="Submit" class="button btn btn-primary" value="<?php echo JText::_('JLOGOUT');?>" />
Then replace the "button btn btn-primary" classes with "submitLink"
This should get you closer and then you can tweak the styling to match your page better.
-Melissa