public_html
directory.oc-includes/osclass/install.php
from your browser:http://example.com/index.php
or directly to http://example.com/oc-includes/osclass/install.phphttp://example.com/classifieds/index.php
or directly to http://example.com/classifieds/oc-includes/osclass/install.php
This will lead you to osclass inbuilt installer.