I entered the sale of a car that was used for business, but entered incorrect amount in one section. I am not able to access those fields again. How do I get back there?

It feels counter-intuitive but you need to go back through and answer the same as you did the first time. Go as far as you can,  the same as the first time. Once you have gotten back in all the way, you can begin to delete information and change information. This is a last in, first out operation. If you change the information too early, the program will keep holding the old information deeper in the back of the program.

You might want to go to Tax Tools > Tools > Topic List.

Look for your auto information there, click on the correct words and the program will take you to that point of entry.