Using the GS-911 Downloader utility on a Windows PC:
Get the GS-911 Downloader utility from the downloads page. Launch the utility, connect your GS-911 interface to the PC's USB port and press the "Download Options" button on the Downloader window. This will open a web page in your web browser that shows the list of downloads for your device. That same page shows your current registration details and allows you to change them.
Using the GS-911wifi Utility on Windows OR Mac OS X:
If you own a GS-911wifi interface, get the GS-911wifi Utility from the downloads page. Launch the utility and connect your GS-911 interface to your computer's USB port. Wait for the utility to detect the GS-911 device, then press the "Device Registration" button. This will open a web page in your web browser that shows your current registration details and allows you to change them. Remember to close the browser and press 'OK' when done.
Using the GS-911wifi iOS or Android mobile app:
If you own a GS-911wifi interface, get the GS-911wifi mobile app if you do not have it yet (see the downloads page). Make sure your GS-911wifi interface is set to infrastructure mode and connected to the same Wi-Fi network as your iOS or Android device. Launch the GS-911wifi app and select your GS-911wifi interface from the list. Go to the "About" menu, then "Registration" and select "Change registration info". This will open a web page in your web browser that shows your current registration details and allows you to change them. Press 'Return to device' when done.