With these commands you will be able to restore your node ID that you have previously backed up.
We shall use Putty and Windows PowerShell.
First to transfer the keystore folder back to the Raspberry PI with PowerShell.
> scp -r keystore pi@raspberry_ip:/home/pi/
Open Putty to change the ownership and move the folder to the correct location.
$ sudo chown -R mysterium-node:mysterium-node keystore
$ sudo mv keystore /var/lib/mysterium-node/
Now you can start Mysterium with your node ID.