To edit your V-81 form, choose "My In-Service Benefits" located on the left-hand side of the page. You will then see your submitted V-81 form in blue at the bottom of the page under "User of Public Transportation." You may edit all V-81 forms that have yet to be approved by clicking on "Edit" located next to the name of that particular V-81 form. Once you have finished entering the updating information, review and then hit the "Submit" button located at the bottom of the page. Any edits that you have made will then be sent through the approval process.
See also:
What is the V-81 Transportation Form?
How do I get reimbursed for travel to do my assignment?
Why would I need to use a vehicle or public transportation?
Where can I find the V-81 Form?
What happens if you use more than one mode of transportation?