In the Lifecycles main window, display the list of lifecycles in the content pane by clicking the top node: 
in the navigation pane.
Click the name link of the lifecycle in the content pane. The Edit Lifecycle dialog box appears.
Select the state for the transition you want to edit in the Lifecycle Model.
Select the transition in the Transitions area and click the Edit Transition button: 
Update the roles on the transition as necessary.
Click OK to update the transition.