Hello.
I tried to install my Homematic HM-MOD-RPI-PCB and the light actor on rpi 3 with openhab2…
The homegear documentation says I have to add something to boot/config.txt etc., but here I have no access… How can I login as root user to edit my files? 
Thanks a lot in advance!!
PS: I am using openhabian on rpi3
Did you try to add sudo in front of your shell commands?
for example: sudo nano /boot/config.txt
That would open the file /boot/config.txt in nano (an editor); you can then edit (and save) as you have root privileges by using sudo.
I’m using WinSCP…
I tried to allow Root Permissions to SSH and it worked. After I finished the configuration, I’ll disable it. Thanks a lot!