I have an older Mac (2012 Mini) which I am expecting to replace, and use as a spare in another room. It came with OSX installed and has been updated through several OS versions to Catalina, which is the last supported version.
I would like to totally wipe it and start over, changing hard disks at the same time. I don't really understand how MacOS licensing works, or how I can do a clean install. I don't want to find myself in the situation I have a Mac I cannot use to download/run an installer!
What is the correct process?