Well tried a second time and it got further, managed to install the samsung modem, but then it sat for ages on the update screen and didn't move. Was again very scared that I might have bricked it...but after I unplugged it, it restarted again. I got a force close but at least it seems to be mostly there. Now I've got it off and recharging again for the third attempt. Managed to find the firewall settings and turned them off, so fingers crossed!