Copy mother blog to sub-blog

Hi!

I run a multisite.

I have until now had my main project as my “mother site” (where you land when you visit my main address: https://www.kultursommerleir.no).

For all the other projects I’ve created new sites (sub directories).

But now, I’d like to move my entire “mother site” to a sub directory since I’d like to have a new “main site” where the visitor can choose which project site to visit and be go from there to the correct page.

How can I create a new “main site” and move my existing main site to a sub-site (sub directory)? I need to move absolutely everything: pages, posts, comments, pictures, you name it. I want a complete replica of my existing main blog but as a sub-site.

Thanks for all help people =)