There is no way to cease the production of breast milk. If you choose not to breastfeed or want to discontinue breastfeeding, the following will assist in allowing you a break to return to normal as quickly as possible:
Wear a good, supportive bra.
Avoid stimulation of the breast, especially the nipples.
Use Tylenol or Ibuprofen as needed for discomfort.
Cold cabbage leaves applied to the breast may be helpful, or an ice pack.
It will usually take several days for the engorged breast to return to normal.