Determine which of the two pins is the easiest for you to hit based on your normal bowling method.
Aim at one side of that pin. Do not aim for a direct hit that will drive the pin backward.
Roll the ball with a slightly greater speed than normal. With luck, the ball will strike the pin on one side and force it to ricochet off the side or back of the lane. With a good bounce, that pin will bounce or slide over to the other side and knock down the other pin.