'98 ZX2 - Tension Release for Alternator

What's the easiest way to release the belt tension when re-installing an alternator on a 98 ZX2? Every alternator I've ever replaced has always had a bolt that the alternator itself swivelled on to release and tighten the tension. This one doesn't :(

the tensioner, put a 1/2 inch wrench on it and pull back (towars the rear of the car) andit will releive belt tension. it's next to the water pump.

Acutally you have to tighten the bolt, so pushing the socket or wrench towards the headlight, not towards the firewall.

I guess it all depends on weather your doing it from the top or bottom.