Default [Q] Root attempt gone wrong

Hi All,

I've attempted to root my SM-900, using Odin 3.09 and followed all the usual steps.
Suddenly I got different coloured horizontal lines on screen and that probably means my attemp didn't go that well...

I've read I should go back to the original firmware using kies, and then try again.

So how do I restore the original firmware?
I have an image (.img) and understand I need samsung Kies.

Question: Do I use Kies or the new KIES3?
How to go from there?

Or is there another way to restore the firmware?

Thanks in advance!