The net UX is the newest gateway from net. Details on the UX are available here
It is all web based, and I have to say the Web UI is pretty good, making it much easier to manage than the previous VX gateway with a combo of apps telnet (although with the apps and telnet comes a lot of flexibility).
Firstly you will need the latest firmware, which you can get from the net website with the appropriate service contract.
Open the net web interface, and go to Tasks, Firmware Upgrade
Browse to your new firmware file and upload
There isn’t much insight into what’s going on, it may hang on upload status for 10-30 seconds
Once the upload completes you will be on this screen for a minute or so
The page will auto refresh, and you may get a timeout, don’t panic, it seems the refresh time is slightly shorter than the boot time
After another 30 seconds or so the gateway should be back up on the new firmware
If you look at the settings, you should see the new firmware version. The system runs on an A/B partition system, which is pretty smart for easy changes/rollback.