Finally got around to doing this. I used this workshop guide page (http://workshop-manuals.com/skoda/octavia-mk2/vehicle_electrics/electrical_system/lights_lamps_switches_outside/headlights_with_xenon_discharge_lamps/headlights_with_xenon_discharge_lamps_up_to_my_08/convert_headlight_for_left-hand/right-hand_traffic/).
However, it is wrong for the left lamp. The switch is behind the hole in latticed plastic piece as shown, it is on the other side. At least I hope it is the manual that is wrong and not that I have an incorrectly manufactured light unit.
I'll test it when it gets dark to see if the beam is now flat.
Thanks for all the help.