We got an email with the details about 24 hours before we were due to arrive. It encouraged us to download a mobile app which could be used to open our doors, operate lift, etc.
They also email you which of the three lifts to use: C1, C2 or C3 which are clearly indicated. Its on a very quiet road/cul-de-sac, so when you are trying to get into the lift or figure things out around there – it won't be busy – you won't have traffic up your ass!
However, this is where it did get a bit messy. We initially drove up to our allocated lift (C1) but the app would not open the door. We ended up driving around to the reception to check-in where the wanted a copy of our passports as we were not residents in Germany. They then give us typical hotel keycards, which we used to operate the lift. So never actually used the app in the end.
If you want it to go smoother – to give your family the best possible surprise and experience – I suggest you contact the hotel reception ahead and possibly discuss. Maybe if you send them passport details they'll activate your app access ahead of time.
Enjoy it – its a great hotel – nice design and the top floor food/drinks is very impressive. Let me know how you get on and post pictures!
