How to do a firmware update for GE Dishwasher that won't run?

I was told by a service technician who repaired my GE refrigerator and updated its firmware that my GE Dishwasher, model CDT835SSJ0SS, needs a firmware update to operate. The dishwasher won't run properly until I do. The firmware update corrects a problem with the appliance reading the touch panel. (GE replaced the panel twice and it still won't run.) I want to be able to do the firmware update myself but the device that enables the update is only available to licensed technicians. NOTE: If I had access to that device, I would have been able to repair my refrigerator on my own and saved a few hundred dollars.

The refrigerator and dishwasher have a lot of diagnostic information that we are not able to access without that device and I don't think it is fair. I am not a licensed service tech but I want to be able to read the information and do easy repairs like firmware updates without having to call GE.