IF YOU ARE UPGRADING 2.*versions to 3.*:
Delete: admin\includes\functions\extra_functions\ssu.php
Delete: includes\classes\ssu\core
Delete: includes\classes\ssu\languages
As of beta 2.5, you can turn SSU on-off, and it's off by default, so you need to turn it on in admin.
If you are upgrading from 3.x to 3.6.x
These actions are OPTIONAL, you can leave these files/folders there, but remove them will make things cleaner for you.
1. Remove “ajax” folder
2. Remove “admin/javascript/inlineeditor.js” file
3. Remove
“admin/images/icons/ssu_delete.gif”
“admin/images/icons/ssu_status_0.gif”
“admin/images/icons/ssu_status_1.gif”
4. Remove “admin/includes/ajax.common.php” file
5. Remove “admin/includes/ajax_javascript_function.php” file
6. Remove “admin/includes/functions/extra_functions/ssu_xajax.php” file