You can edit several test cases at once by using the Edit in Bulk feature.
1. Mark the checkboxes of the Test Cases you want to edit, and click on the More button. Select the option Edit in bulk... from the dropdown menu.
2. Mark the check boxes of the fields you want to edit, then input or select the new values for the marked fields. Notice the amount of Test Cases selected is displayed on the top of the page.
3. Scroll down to see the remaining options. Once you are done editing, click on the Confirm button.
4. Make sure the amount of Test Cases selected is correct and Confirm the Update Test Cases alert.
5. There you go, your selected Test Cases have been modified in bulk, with the new values for the marked fields on the editing process.