First you must navigate to the Modify Travel Authorizations page.
Once you click on 'Modify' you will be brought to a search page. The default Search By parameter is Authorization ID. You can search by that, if you have the Authorization ID, or choose another parameter to search. Alternately, if you leave the field blank and click Search, the system will list all TAs that are eligible to be modified.
Remember, you can only update TAs that haven't been submitted yet, or have been submitted and then sent back by an approver.
If you have only one eligible TA, the system will open it automatically; otherwise the system will list the TAs, and you can select the appropriate one by click in the Authorization ID hyperlink.
If you are modifying a Travel Authorization that has been sent back by approver, you will see a page like the one shown below. At the top of the page, in red, you will see 'Sent Back for Revision' and a hyperlink with the approver's Comment (click the hyperlink to see the rest of the comment, if necessary). Take the action noted in the comment.
If the TA has never been submitted, you will not see the text and hyperlink in red, nor the Action History at the bottom of the page.
You can perform any action on the TA that you could do while creating it; add or delete lines, change amounts, dates, locations, etc. Similar to new TAs, you can also Save for Later. When you are finished, be sure to click the Submit button.