From Vienna: via the A2 exit Fürstenfeld Ilz, continue via the 319 to Fürstenfeld
You can find detailed information on how to get here.
With the BusBahnBim app from Verbundlinie, timetable information has never been easier: all bus, train and streetcar connections in Austria can be queried by entering locations and/or addresses, stops or important points. The app is available as a free app for smartphones (Android, iOS) - on Google Play and in the App Store.
The Thermenlandbus also takes you directly to Fürstenfeld on the fastest route.