If you want to stop breastfeeding for any reason, you can do this quicky in the following way:
Stop the feeding schedule you used to keep. Only use suction if you feel pressure in your breasts, or if you start to leak. Use suction compressors in your bra. Only pump if your breasts indicate that it's necessary, and only for five minutes or so: just enough to provide relief. You may find that you don't need to pump within a few days.
Your milk production should stop soon. Keep an eye on your breasts, and feel them when you're showering - they should not be painful. It's possible you may have a few drops of milk for a few weeks or couple of months if you put pressure on your breast or nipple.
Also see these information articles: · Breastfeeding · Benefits · Bottling · Breastfeeding diapers · Changing food · Clustering · Duration · Empty days · Let down reflex · Menstruation · Milk channels and breast inflammation · Milk production · Nipples · Physical consequences · Positioning · Reasons to stop · Tandem feeding · Thrush
From Cassandra-Harmon In Q&A