The first question is obviously why would you want to do this and it may be simply that you have sufficient water pressure to serve two zones at the same time, this reducing your overall watering time.
Ok – so this is not complicated…
Assuming you want to run station 1 and 2 together, simply remove station two wire from its terminal at the controller and put it into the same terminal as station 1.
Yep – that’s it. When the power to terminal one comes on it will run both solenoids.
Of course if you wish to make sure a solenoid no longer works then you can do the reverse. Remove its wire from the controller. To be safe you really need to eliminate the solenoid all together and cap the pipe as sooner or later it will fail and if its been covered over with bricks or liquid limestone then it becomes and expensive repair exercise.
For help with any of these issues call Andrew on 0400044236 or email firstname.lastname@example.org