To change mileage:
1. Click Federal on the left-hand side
menu.
2. Click Income & Expenses across the top.
3. Scroll down to Self-Employment and
click Show more.
4. Click Start or Revisit by Income
and Expenses.
Go into the business that you'd like to change.
Click Edit by Vehicle under Expenses. Continue through till you get to the screen below to change your mileage entries.