KH Laser belts

[Squish]

Hi guys,
Basically I'm stuck trying to change the belts on my 94 KH GL. The alternator belt snapped the other day, and I thought while I changed it I'd do the air con/power steer belt too (since you seem to have to take it off to get to the other belt anyway).

The problem I've run into is getting the tension off the power steering belt. I've undone the lock nut behind the pulley and the tension nut at the front of the P/S pump. But the thing won't move. Is there any trick to it? Have I undone the wrong nuts? I need this car to go to Sydney tomorrow so it's kind of urgent.

Any help would be much appreciated.

Cheers,
Ben.