Moving Main Blog

I have a Multisite subdomain setup and I’d like to relegate my Main site to a subdomain and promote a subdomain to the Main site. Is there a clean, ie straight-forward, way to do this? I reckon I’ll export posts and then I can import for each respectively, but was also thinking I’ll need to do something with databases. I don’t expect that I’d need to export everything from the root, since it has all of the plugin information and that isn’t necessary for the subdomain. Can someone direct me to what should be exported?