If you stopped a long time ago (btw- how long ago was that?) then you may need to see your doctor about lowering your Prolactin levels. There should be something out there that will help "dry you up".
It should stop by itself... but it will take some time. Your body adjusts to the milk that the baby is demanding... so if you have stopped nursing it will take your body a little while to realize the baby doesn't need the milk anymore.
A few tips... DON'T pump, unless you absolutely need to because its too painful... and then ONLY pump enough to be comfortable. Avoid long hot showers that would cause let down. And wear nursing pads until you dry up. I promise it will happen... it just takes awhile.