Short answer: cabbage leaves in your bra.
I just stopped pumping after doing it exclusively for 11 months. I did everything I could to taper down my supply gradually over several weeks. even though my supply declined I kept making lots of milk and my breasts were always engorged and painful.
This went on for weeks and I wasn't sure what to do. I had read about using cabbage leaves as a homeopathic remedy to dry up breast milk and thought it sounded ridiculous. I reach the point of feeling desperate and figured "what the hell - cabbage leaves won't hurt anything...
within 3 days my breasts felt pretty much empty and I had no further pain. I smelled like coleslaw, and still don't understand the science of it, but it was worth it. I'd recommend Savoy cabbage since the soft leaves conform nicely to bra shape - LOL.