Move subfolder to root — and vice versa

Hello!

I run a Multisite installation of WordPress. There’s the main blog, in the root domain, e there are other 5 blogs in subfolders.

I’d like to promote one of the subfolders as root, and vice versa, I mean, to move the current root to a subfolder position. Like this:

Let’s suppose the domain example.com and one of the subfolders as example.com/hello. The idea would be the /hello going to the root example.com, and the current example.com going to some subfolder that I will create.

Technically, I have no idea about how to do this. Any help, please?

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