DynaDNS Bonjour and DNS Service Discovery

Ok I have been useing the Time Capsule from the time it came out I am exspanding my home network and am trying to do it as layed out in this link

http://dyn.com/support/airport-time-capsule-with-dynamic-dns/ and http://dyn.com/support/bonjour-and-dns-discovery/ but I can not find the settings shown in the screen shots I have firmware 7.6.1 and airport utility 6.1 can I roll back the firmware or get an older copy of the utility so this can be set up? or is it just hidden in a difrent spot.