PlayOnMac made it trivial.
Download it, copy it to the Applications directory (that's how Mac users install stuff), run it once to set stuff up. It'll install everything. Let it install XCrystal (just trust me, it'll do everything automagically). One reboot.
Double-click the Director. It flippin' runs. Set up the Director like the Windows users do. That's it. You're now running the Director on a Mac. ProxyList FTW!