The unit planner is only available in Cc Pro.
To move a unit, simply hover over it until the move icon appears. You can then drag a unit anywhere on the timeline. If you want to swap two units, simply drag the second unit backwards to the first day of the first unit. You will see the first unit jump forward and the second unit drop in place.
Note: The unit planner is only available in Cc Pro. Click here to learn how to sign up for a 30-day, FREE, trial.