How do I style the page with the message on it?

Having an issue with being able to edit the page with the message that reads “You need to login to view this content. Please Login. Not a Member? Join Us”. I know I can download a plugin that allows me to edit the actual message itself, but thats not my issue. I am having an issue with the layout being messed up and not being able to gain access to anything remotely close to what is on the page. I can edit all the other pages like join us and the register page but I cant edit this simple issue? Ive looked through all the documentation and found nothing, also on the forum itself it seems like others are looking for the solution to this issue without any response.

Here is the url to the page I am referring to: [http://standardpub.com/samples/]