Hi, I'm looking to use my external hard drive connected to my Mac Mini as a Time Capsule? I want to backup both the Mac Mini AND my Macbook Pro (via Wifi) to this external drive. How do I make it work? What do I enable on the Mac mini for the Macbook to find the external drive over the wifi? All guides are so confusing. Do I need to have an Airport router for this, or will it work over wifi on any router? Thanks!