Where do you change the built in templates?

I found the page that lists the built in themes here http://stackideas.com/docs/easyblog/layouts/182-themes-templates-layout

but the page does not explain how to activate those themes. Nor can I find a page that explains how to do that. Can someone please help me or direct me to a page with the instructions on how to change the default templates that come with EasyBlog?

Thank you.