Normally with B&S engines, you just remove the cooling air cowl so that you can see the flywheel. You'll find the magneto mounted very close to the flywheel, so it can pick up pulses from a magnet in the outside of the flywheel. The magneto should have the spark plug lead coming out of it, plus one other lead: the kill wire. I'm not familiar with the Intek engines - please post a picture of your magneto and its surroundings when you take the cover off, for the benefit of many members here. It is possible there will be a terminal for the kill wire rather than an actual wire. Grounding the kill wire short circuits the magneto primary and stops the spark. This is more or less a universal technique for stopping small modern magneto engines (though there are engines that rely on an external 12V supply and a flywheel-timed coil ignition system - but do not apply 12V to your B&S magneto kill wire, or you will fry the magneto).
