Unzip app files into /boot/ICU/

Run Putty, login and start Midnight Commander using 'sudo mc' to unzip the files into /boot/ICU/.

In the right panel navigate to the /home/pi/ directory where the zip with the app files was copied with WinSCP.

In the left panel navigate to /boot/ICU/.

Double click the zip to open it.

Mark all the files from the zip using right mouse button.

Click "Copy" to copy them to the /boot/ICU directory.

The files were copied.

Click Quit in right bottom corner to close MC.

Enter

sudo reboot

to restart S2GW.

During the reboot the app files will be moved to their working location. They will disappear from /boot/ICU/.

The restart will close the Putty connection so you will need to reconnect if needed.