UK headlight alinement for XK8 in Europe

I recently brought my UK reg. RHD XK8 ('99 model) to Spain and have decided to keep it here re-registering it onto Spanish plates. The car needs to pass it's Spanish MOT and the headlights must be adjusted for driving on the right. Without using stickers on the lenses, can anyone tell me how this can be done? Do I need to buy completely new headlight units, just bulbs or is there some sort of switch for this purpose? Can anyone shed light on this?
Thanks GSE