How can I edit dividend Payer's information e.g. Vanguard address is wrong, I can't find where to fix it?

You can revisit the Wages and Income section of your tax return to get to the 1099s you entered.

1. Login to your TurboTax online account.
2. Select "Federal" on the left.
3. Click on "Wages and Income".
4. Look for 1099s. Here is where you can select Vanguard's 1099 information and edit it.

@oddtom

Thanks for your reply, however it didn't work. There is still no way to edit Vanguard address, tax-id, etc. that I entered originally.  I can change the institution name only in the box. Any more ideas?

You don't need the address or even the EIN.  Delete that 1099Div and enter it manually.   Or just leave the wrong address.  

Thanks, I can do that.  It's only the state and zip that's wrong, so if IRS doesn't care I'll leave as it is!  (Volvo?)