How to change the NJ address to PA address of terminated employee for W2 mailing

I'd be glad to help you with this, cleaningserviceb.

You can update the residential address for this inactive employee by following these steps:

1. Go to Workers on the left panel.
2. Select the Employees tab.
3. Under the Employee list section, select Inactive employees from the drop-down list.
4. Click the employee's name.
5. Select the pencil icon next to Pay.
6. Go to the What are employee's name withholdings? section, and click the pencil icon.
7. In the Payroll Taxes Setup and Compliance page, update the employee's home address from NJ to PA.
8. Click Done.

Please see sample screenshot for reference: 

You can also use this article on how you can edit the other employees information in QuickBooks Online Payroll.

I'm only a post away if you need more help. Thanks.