You don't need to do anything to stop producing milk EXCEPT cut out feedings- your body will naturally decrease milk production to match what the baby is taking. Here is what I did with my son (my daughter weaned herself, so it wasn't an issue!):
I cut out the first nursing of the day and gave him a sippy cup of milk instead. I did this for one week to give my body time to adjust to the decreased milk needs. I then cut out another nursing per day for the next week. And so on until he was only nursing once a day at bedtime. Then I cut out that nursing- this one was hardest for him because he was very much soothed to sleep by nursing then. So, I gave him a sippy cup of milk and rocked him as I did when he was nursing. After about a week, I switched the milk to water so he wasn't going to sleep with milk in his mouth. It worked very well for us, and I did not have any problem with engorgement. I guess the only downside was that it took about 6 weeks to completely wean him.\
I hope this helps!
P.