Do you expect that the correction will give you an additional refund, or will you owe more tax? It's too late to get an additional refund for 2016, so if that's what you were expecting, you should just do nothing.
If you owe more tax, you cannot "redo" your 2016 tax return. You have to file an amended return, Form 1040-X, to make the correction. You cannot do it with TurboTax. TurboTax no longer supports years earlier than 2019.
What was incorrect on the 2016 tax return that you filed? Why are you just now correcting it?
If the company that did your original 2016 tax return is still around, you might be able to get a copy from them. That would be the easiest way. If not, you can get a copy or a transcript from the IRS. See the following link on the IRS web site for more information.
Topic 156 - Copy of Your Tax Return – How to Get One
A Tax Return Transcript will list all the information from your tax return, but not in the format of the actual tax forms. A Wage and Income Transcript will list the information from your W-2, but does not include the state information. You can get a complete copy of your W-2 from the Social Security Administration. There is a fee of $126 for each year. See the following link.
How can I get a copy of my wage and tax statements (Form W-2)?
You could try asking the employer if they can give you a copy of your W-2 from 2016, but they might not be able to provide it from so long ago.
