I filed an extension for federal and state taxes. I made a mistake in the amount of estimated fed and state taxes paid and TT will not let me change the value.

[Critter]

Have you tried deleting the tax payments form? 

Here's how to delete forms in TurboTax Online:

1.   Open your return, if it's not already open.

2.   In the upper right corner, click My Account > Tools.

3.   In the pop-up window, select Delete a form.

4.   Click Delete next to the form or schedule and follow the instructions to remove the form/schedule.