Go to the Test Plans page and click the Edit Button of the test plan you want to change.
You will be redirected to Test Suite. If you look at the right side of the Test Suite title you can see that your test plan name will be there. That means Test Suite is in Test Plan Edit mode. You are free to make your changes.
Once you finished your changes, you can save them by clicking the Save button on the Finalize step of the Test Suite.
Starting a New Test From Test Plan
Go to the Test Plans page and click the Edit Button of the test plan. Click the Next buttons until the Finalize step. Ddosify will give a unique test name by default, but you can change the test name if you would like. Click the Start New Test button to start the new test.