Changing my core from a Windows 8.1 Pro laptop to an Apple Minimac end 2012

I want to use my new old Miinimac (version end of 2012 - 16GB RAM) as the Core in stead of my Windows 8.1 Pro laptop. How come?

https://community.roonlabs.com/t/how-do-i-move-my-roon-library-to-a-new-computer/4636

my situation is a little bit different. The Minimac has already his role as a remote for the Windows laptop

Go into your Settings on the Mac, you’ll see something like this:

Click Disconnect, then you’ll get an option to use the Mac as Core.