I accidentally entered that I made a tax payment when I filed for an extension. How do I change that within Turbo Tax?

To enter or delete the amount you paid with an extension (including state extension) go to

Federal Taxes (or Personal Tab for desktop H&B version)

Deductions and Credits

Then scroll way down to Estimates and Other Taxes Paid

Other Income Taxes - Click the Start or Update button

Next page second section Payments with Extension

Either Visit All or Click Start or Update by the extension you paid