How do I modify my total 2023 income and withholding?

[DoninGA]

If you have Not filed the 2023 tax return -

Click on Federal on the left side of the online program screen

Click on Wages & Income

On the W-2 shown, click on the Edit/Add button

If you have filed the 2023 tax return -

You will have to wait for the IRS to either Accept or Reject your filed federal tax return.
If the return is rejected you can make the necessary changes and e-file again.
If the return is accepted you will have to amend your original tax return. An amended return, Form 1040-X, can only be printed and mailed to the IRS if the original tax return was not e-filed. The IRS will take up to 20 weeks or longer to process an amended tax return.

Before starting to amend the tax return, wait for the tax refund to be received or the taxes due to be paid and processed by the IRS.

See this TurboTax support FAQ for amending a tax return - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-a...

[Texas Roger]

For what reason do you need to modify it? Did you mistakenly enter the wrong information? Have you already submitted your tax return for efiling?