ElectroMaster's Stungun???

[LifeForce4]

I am new to electronic circuits, only built two circuits a scrolling message and a pair of dice. I was looking at the projects and saw ElectroMaster's plans for a Stun-gun.

What I wanted to know is: If I change the transformer will that make the it give less of a shock or should I add some resistors?

Thanks for the help,
Kyle