first you must find a disposable camera. I think I used one with the brand name kodak. the reason this works is because of a component in the camera called capacitor. this component is charged, holds its charge, and then will quickly discharge. this of course is useful for the flash in the camera, so do not buy a camera without a flash. (I was originally going to make a flash bang by rewiring the shudders and flash, and by upping the voltage on the battery, but bought the wrong kind of camera, and got the idea for this after shocking my self while messing around with the circuitry. being shocked with this hurts, and it is dangerous so please be responsible and do not use this on animals people or flammable items.
I recently remade one of these with four of the capacitors in parallel. Got some amazing sparks with a deafening crack. here's a video:
this step is very easy. you just remove the cardboard/ paper from the camera and pry open the two plastic pieces that make the housing for the camera. do not throw them away though, I ended up using them for the housing of the stun gun although you could buy a project box from Radio Shack and it would probably work better.