I need to change my business from a schedule C to a Schedule F. how can i do this?

First remove Schedule C, then add Schedule F by following the steps below.

If you need to delete Schedule C in TurboTax Online:

1. Go to "My Account" in the top right corner

2. Select "Tools"

3. Under "Tools Center" select "Delete a Form"

4.  Navigate to "Schedule C" and select "Delete" next to it

To Add Schedule F: 

1. Select "Business" at the top of the screen

2. Choose "Continue", then "I'll choose what I work on"

3. Select "Visit All" next to "Farm Income and Expenses"