Stuttgart
Bürgerbüro Mitte
Eberhardstraße 39, 70173 Stuttgart
Choose a new PIN on the spot, with no need to remember the old one, but you have to come in person.
Bring your Personalausweis. Choose a PIN that cannot easily be guessed from your card, keep it private and do not write it on the card. The PUK can unblock incorrect-PIN attempts only ten times; it does not replace a forgotten PIN.