Hi there, @user09759.
Thank you for reaching out to the Community. I'll help you modify the mileage you've entered manually. I'll show you how:
- On the left pane click Miles.
- Click the appropriate trip, under Distance enter the correct mileage.
- Select Save.
Once you edit the mileage, it will also automatically calculate your Tax deduction.
I've included an article that helps you about methods to deduct the cost of operating your vehicles: About auto, car, or vehicle deductions
You can always find me here if you need more help in modifying your mileage. As always, assistance is just a post away. Have a great day!