So basically you take however many pills you want to dose, dissolve them in some cold water (ideally chilled in the fridge for a while, but cold tap water works in a pinch. generally people use 2ml/tablet, but as long as you keep it below 50ml - 70ml you're fine), once they've completely dissolved you get left with a viscous white fluid, which you run through a coffee filter (pre-dampened to prevent it absorbing your precious drugs), the water runs through into the second cup with the opiates inside it, the APAP is still solid and gets caught in the coffee filter. Throw out the white gunk in the filter, drink the (rather foul tasting) water and enjoy.