realistic sta-52 speaker system

yes i know it's an oldie but i love it. I was running it through a car speaker system untul recently when i picked up a couple of 4 ohm speakers from a junk sale. I checked the back of the sta-52 and it said that the standard outputs hook up to 8 or 16 ohm speakers (whoops) and if i wanted to attach 4 ohm speakers i need to consult the manual. Sadly i don't have a manual. So does anyone know how to hook up 4 ohm speakers to said amp or does anyone have a manual wherin the can wuote the section on 4 ohm speakers?

Thanks muchly

Darren