You and your staff can reset your Punchpass password right on the login page (app.punchpass.com). From there, click on the "Forgot Password" link. You'll be guided through steps to set up a new password from there.
NOTE: These instructions apply to the business management use of Punchpass only. Individual customers of Punchpass-run businesses should access their logins by visiting the business' public website directly. Here's more about that.