hi!
You can use the command " redundancy force-switchover" to force a switchover in which case the redundant will become active and the curret active will be reloaded to come up as a standby.
But the active/standby combination will revertback once you relod the device. Probably you can try swapping the SUPs physically or go with the first solution. You will have to force redundancy everytime you reload the device.
Regards,
Niranjan
(pls rate if helpful)