airport extreme ethernet network file sharing

I was inspired by this post at PixelBokeh that detailed how to use a Mac Mini connected to a large raid drive as a server that could share files b/w our 3 other iMac workstations via Ethernet. Here's the gear we're working with:

• Lacie 5big RAID disk (connected to Mac Mini via Thunderbolt)
• Mac Mini (11.2.6 w/ OS X Server App)
• Airport Extreme (to connect Mini to other Macs via Ethernet)
• 2 x iMac Retinas (video editing stations 1 & 2)
• 1 x Mac Pro trashcan (video editing station 3)

In an ideal world, we would want to mount the Lacie as a network disk on our video editing stations to access some files without having to shuttle a bunch of little drives around.

Everything is plugged in, but I'm having a hard time with the networking aspect. How can I get the video editing stations to mount the Mac Mini via their Ethernet connection?