To delete a transition from your DES, make sure you have Selection mode enabled.
Disable all DES components in the left pane.
Select the transition you wish to remove by clicking on its transition line. Now click the Delete button
on the toolbar . Alternatively, you can right-click on
the transition line and select Delect or simply press the Delete key when the transition
is selected. You will notice the transition will be removed from the DES editor workspace and from the
Transition pane.