1. Download the update utility if you don't already have it:
Please go to upgrades.pure.com/uk
Bitte gehen Sie auf upgrades.pure.com/de
Allez sur upgrades.pure.com/fr
Si prega di andare a upgrades.pure.com/it
2. Run the utility. Change language if desired, click through Welcome screen and accept licence agreement if you agree.
3. Connect your radio via USB and put it into Upgrade mode as shown on screen. Windows will search for device.
4. At Save backup screen, enter Debug Mode by pressing the Ctrl+Shift+F1 keys on your keyboard. The title bar changes to [DEBUG MODE] and now extra functionality such as skipping backup and choosing the location of the firmware image file to be installed will be available. The default is to skip the backup since you are rolling back so most likely have the later firmware anyway.
5. Choose firmware image file: When prompted to choose firmware image, click 'Specific software file' and browse to location where you stored the backup from previous upgrade (it will have a .dfu extension if you accepted the default name):
6. Follow the on-screen instructions to complete the process.
I hope this information has been useful.