use a very hot towel to put on the breasts, then press very hard toward nipples to express the milk...... it's very very painful believe me!
u should ask someone to help, otherwise u will be very tired!
but if u handle it well, it'll gone after few days!
also, don't drink any soup, even not a fish soup, becoz it'll make your breast full again!
I know how it feel, I had this before. My BB now is 3 months.
Like other mothers said, use a milk bottle with hot water, "full" on your breasts and massage/ press added, it will be better.
Remember that you will keep doing this, don't give up (I've tried to do this for whole day), than your breasts will start to release milk, than you will feel better.