[Plugin: NextGen Gallery] Simple link to attachment.php

I’m losing my mind. When you insert a standard WP gallery you have the option to use an attachment.php or image.php file when the thumbnail is clicked. I’ve spent 3 days trying to figure out how to do this with NextGen Gallery and I’m lost. I’m new to both php and WordPress so if one of you kind folks knows how to do this, please use very basic wording to explain it to me. Thanks a million to anyone who can help! Paul