If the PIN code is locked, open the Smart Security Interface (or SecureDoc, in case of MacOS systems) application and go to the "Unlock token PIN" tab (in SecureDoc - "Settings" tab >> "Change token PIN").
In the SO PIN field, enter the SO PIN code from the secure envelope (in which the SO PIN code was provided), and in the remaining 2 fields enter a new PIN code.
ATTENTION! If the SO PIN will be entered incorrectly three times, the cryptographic card will be irreversibly locked.