Apparently, by requesting it from the state, and fulfilling a whole laundry list of requirements. Including exams, background checks, disclosing financial information, adding an alarm system to the car, and more: https://www-bussgeldkatalog-org.translate.goog/taxikonzessio...
This also mentions that a concession cannot be sold, but if an entire taxi business is sold, the concession can be sold with it. It expires after 5 years however.
I still don't understand how what is going on in New York has anything to do with taxis in Germany. Whatever Germany is doing seems to work, and whatever New York is doing apparently not? I don't know, I'm not familiar with NY taxis.
This also mentions that a concession cannot be sold, but if an entire taxi business is sold, the concession can be sold with it. It expires after 5 years however.
I still don't understand how what is going on in New York has anything to do with taxis in Germany. Whatever Germany is doing seems to work, and whatever New York is doing apparently not? I don't know, I'm not familiar with NY taxis.