I would suggest massaging as you pump and feed.
When my milk first came in, I had this same problem. So when I would pump my H would help me by massaging the "hard" spots to help empty the breast.
If you are not emptying the breast, baby is only getting foremilk and you want him to get the hindmilk. Try rubbing with your thumb from the top of the breast to the bottom where they are hard.
Cabbage leaves are used to help dry up the breast, so I wouldn't advise you doing that.