Upgrading+Using Early 2009 Mini for iTunes 12
I have an early 2009 Mac Mini that I would like to use to store all of my iTunes music so that I can play music from the Mini through a bluetooth speaker. The problem is that I'm a neophyte when it comes to something like this, and so I don't know how to access my older Mac Mini from my iMac, which is running Yosemite 10.10.3.
I have the Mini connected to my iMac via ethernet, but that only gives me access to the hard drive. I assume I will need to upgrade the Mini's operating system in order to allow it to work with iTunes 12, but, again, I can't access the the actual system, just the hard drive.
If someone can walk me through the steps to virtually mount the Mini disk onto my iMac and help me set it up with iTunes, I'd greatly appreciate it. Please know that I have, indeed, Googled just about every different phrase I can think of to find the answer to my questions all, unfortunately, to no avail.
Thanks!
iMac, OS X Yosemite (10.10.2)