How can I log out my authors?

Hey guys. My website is under maintence so I enabled “coming soon” mode, so people can’t see it. However I would like to make it only visible for the administrators, and not the authors, so I’ve changed the login URL, and now I’d like to know if there’s any way to log out everybody. Or is there any way for only the adm to see the website while in coming soon mode? thanks!