Yes this is a super easy fix. What you going to do is go on to EFTPS and log into with your old password. Then you can change your password and you cannot have any two letters the same back to back just FYI. I think you need a capital and a number and a symbol. When you use a third party like QuickBooks, EFTPS now requires that you change your password once a year. 

Then, when you log back into QuickBooks you will enter your new password your PIN is the same. You need to do this every year. 

As for the penalty the IRS will most likely waive it they have been very good at waving penalties this year. 

I am an accountant and a QuickBooks pro advisor with over 30 years experience,  with QuickBooks desktop.