How do I get back into my 2018 tax return? Not to amend it but to go to the part where you can play with the numbers to estimate 2019 tax payments?

[IreneS]

To get back into your return after printing or e-filing, please follow these steps:

1. In TurboTax Online, sign into your account.
2. Select Tax Home in the left menu.
3. Scroll down to Your tax returns & documents.
4. Select 2018, and then select Add a State (you're not actually adding a state, this just gets you into the right menu).
5. Once you're in your return you can navigate around.
6. To get to the estimated payment calculations, click Federal > Other Tax Situations.
7. In the Other Tax Forms section, click the Start box next to Form W-4 and Estimated Taxes.
8. On the screen, Adjust How Much Tax You Pay, click No.  (This for withholding from your paycheck.)