Need site set to private

This is my client’s site. They created it a very long time ago, and don’t have the email credentials anymore.

We cannot prove ownership. All we can show is that we have a current site that is 100% relevant and contains current information, whereas this www.ads-software.com site hasn’t been touched in a decade.

Is there a way it could be set to private so the world doesn’t see it? I know it cant be deleted without proof of ownership.

The page I need help with: [log in to see the link]