You can edit your
business expenses in TurboTax Self Employed here:
- Business
- I'll Choose What I Work on
and Business Income & Expenses
- Start or
Update
- Click "Edit" next to your business
name or if none click "Add Business"
You will then be on
your page about your business and you can scroll down to Business Expenses and
Business Vehicle Expense to change your business
mileage.