Tip #3 Using old Airport Stations and Utility in Mac OS 10.9 Mavericks and later
11/06/14

I got a lot of Questions from customers about how they would be able to use their old Airport Express with a new computer. The old Airport Express G and N need the Airport Utility 5.6.1. This version doesn’t work under Mavericks as Apple has change a Framework inside the system. There is a way of using the old Airport Utility by altering the Framework but it needs to be done every time you want to launch the old utility.
I went online and searched for an easier solution. What I stumbled upon is a nice tutorial on how to do it and a ready to use Utility including a special launching script to go with it, so that the user won’t have to change the Framework every single time.

Instead of posting the whole thing again I though “Credit where credit is due!”. Here is the link to corey mahler, the guy who fixed my airport utility!