All you have to do is download, install it, enable it and then it does the rest for you. It auto generates the thumbnails and code to open your images up in a Lightbox. So simple!
Thanks for making such a great extension free!
I use this plugin with 'articlesanywhere' which allows me to place articles inside the tabs making it a very efficient way of placing whole articles inside the tabs of this plugin.
Great stuff developer - keep up the good work!