Changing timing and balance belts

I'm trying to replace the timing and balance belts on my 91 honda accord. I'm going by what the auto book tells me. I have to get the pulley off and it says to stick a screw driver in one of the holes on the back of the engine which will give Resistance when I try to take of the pulley. Well it caused both belts to break.

So now what? What should I do so I can get the main engine pulley off.