The checkin was pretty easy - I got an invitation code for the digital lock. One day before I arrive I had to install the "Nuki" app, enter the invitation code and thats it. The lock works via Bluetooth so you do not need a Internet connection to open the door. You can simply push a button in the app to open the door - so please be careful to always have enough battery.
I arrived at the international bus terminal (Flixbus). From there I took the Subway U3 in direction to Ottakring. Switch to U4 (Direction Hütteldorf) at Landstraße. At Meidling Hauptstraße you should leave U4, from there you can walk the last two Minutes
The location is perfect to explore the city. With the subway U4 you are in the middle of Vienna after 3 Stations. To Schönbrunn it is only one station in the other direction.