Your password is your pin.
Patrons with email addresses on their account can reset their PIN using the "Forgot your password?" link on the catalog - https://catalog.hmcpl.org/cgi-bin/koha/opac-password-recovery.pl
This will send a password reset email to that address.
NEW: Watch a tutorial video on how to reset your password: https://www.youtube.com/watch?v=P2wmqKfmyBQ
If you need further assistance, please email us at askus@hmcpl.org