Goodmorning,
In this evening i want to buy a cubase 10.5 from another guy. He bought it in a store last year
and i want to buy it from him. How can i registrate the cubase and dongle for my name / account ??
Thanks for your answers 
Greetz from Rotterdam,
Onno
Go to the Steinberg page (or use the Forum search) and search for “Steinberg Software resale wizard”.
Basically he unregisters, then you Register.
yes, you will also need to create a My Steinberg account.
that account is used to register your software, and keep records of the software you own.
the steinberg shop (to purchase software) is a seperate account and a completely different system.
different user names, different logins, and different emails Potentially.
personally i find that aspect a bit stupid.
Spaceman
Separating the steinberg SHOP from the other account is definitely a good solution - in terms of protecting user/owner data and separating it from payments.