Have your water in a relatively high simmer in a deep pot. Have a glass cup/jar whole milk placed IN the pot of boiling water, then add your bud to the bud. The heat will extract the goods into the fat of you milk. So you fatty milk with ground up / finely chopped bud in it placed in a glass jar, then place the glass jar into a pot of hot water. Stir often.

In other words:

Put milk and cannabis into a double boiler
Cook on medium heat for half an hour, stirring often
Strain cannabis from milk and discard
Store milk in an air tight container in the fridge.

The THC dissolves into the milk's fat, leaving you with a liquid (milk+THC) and the plant, which has very little THC left. Use a sieve or soemthing to filter out the now-useless (to get high from at least) plant, and you're left with the milk+THC. Goes great with Lucky Charms.

I've yet to actually try this, but common sense tells me that this will work.