I have a site inside a multi-site network. I would like to detach it and transform to a separate/independent site. How can I do it?
By reading all that Ipstenu has published.
Multisite 101 > Advanced Topics > Exporting a Site
If you want to export one site from the network and install somewhere else, you will have to make a couple important decisions. If all you care about is the content, a traditional WordPress export will be just fine. You can simply import the content on the new location, be it a separate install of WordPress, or just a different site on your network.
If you need to keep the look and feel of your site, all the plugins, theme settings, and users, it’s vastly more complicated. The basic steps would be to:
You’re going to have to do some work in the database, so now’s the time to get some coffee and practice not freaking out.