Something went wrong in the upgrade of my Ubuntu 13.04 to 13.10

The upgrade basically crashed halfway through. On booting I was thrown into a maintainence screen. I found some online instructions for fixing with the package manager ... Which seemed to do a lot of setting up. But then crashed saying package is in a bad inconsistent state.

Now I'm in a position where Ubuntu starts again, but goes into a low-res screen and there's no WiFi. I have no Ethernet cable connection but I did download the 13.10 iso on another machine and put it on a pen drive.

So I'd like to know there's a way of asking the machine from inside Ubuntu to redo its upgrade from the data on the pendrive rather than WiFi.

Is this possible?

Cheers

Phil