$ ykman fido access verify-pin 
Enter your PIN: 
ERROR: PIN verification failed: CTAP error: 0x32 - PIN_BLOCKED.

$ ykman fido info
AAGUID:             1fc0579f-8113-47ea-b116-bb5a8db9203b
PIN:                Blocked
Minimum PIN length: 4

$ ykman fido reset
WARNING! This will delete all FIDO credentials, including FIDO U2F credentials, and restore factory settings. Proceed? [y/N]: y
Remove your YubiKey from the USB port.

Re-insert your YubiKey now...
Touch the YubiKey to confirm.
Reset in progress, DO NOT REMOVE YOUR YUBIKEY!
FIDO application data reset.

$ ykman fido access change-pin
Enter your new PIN: 
Repeat for confirmation: 
FIDO PIN updated.