There are two ways on how to update it, BalBkpg17.

You can let them log in to their QuickBooks Workforce account and update it from there.

1. Go to the Gear icon and select Account Settings.
2. Click the edit icon beside Email Address.
3. Enter your new email address and verify current password.
4. Select Save. A confirmation will be sent to your new email address.

If they no longer have access to the original email address, you/they can send an Email Change Request:

1. Fill out this form: Email Change Request.
2. Be sure all details match the information in the account, then click Submit.
3. They'll receive a confirmation email, then sign in again.

I'll be happy to assist you if you need more help. Take care!