I entered the wrong amount on Schedule C Vehicle ending mileage and can't change it, how do I do this. It is in blue numbers?

Blue numbers indicate an amount that you entered. You should be able to change it.

Where exactly are you trying to change the number? You said "Can't Change incorrect # here." I don't know where "here" is. We can't see your screen. Are you looking at the Car and Truck Expenses Worksheet in forms mode, or are you seeing it in Smart Check (Federal Review, checking your return for errors)? Are you trying to change the ending mileage on line 5a? What happens if you click on the number and press Delete or Backspace? If you can delete it, can you then enter the correct amount?

Are you using the desktop TurboTax software or TurboTax Online?

You posted your question in the "After you file" section. Did you already file the tax return with the wrong ending mileage, or are you still working on it?

If all else fails, delete the vehicle and enter the vehicle information again.