Well, I'm pretty sure cats (and young kittens especially) aren't really supposed to have cows milk to begin with
From what I remember, you just put the food out and put them next to it. They will climb into it and get themselves filthy lol. This may take a few times until they realize it tastes good
You can put the momma cat in another room so she doesn't steal it all
I think they wean between 6-8 weeks. More towards 8 if I remember correctly
You know, I still call it milk eventhough I know it's KMR. Just a force of habit. Though it is true, cow's milk isn't great for kittens and many cats are actually lactose intolerant. You can use is as a temporary solution if you throw an egg yolk in it. A better option, according to the literatue is goat's milk. But this is for another topic entirely.
You can begin the weaning process as soon as the teeth have come in. I waited until 4 weeks, when I could easily see and
feel teeth. I did teach my kittens lapping first, though only about half really got the technique well. The rest kind of/sort of decided that they hated KMR and went straight to licking, or more accurately sucking food away from my fingers. So, I was the one who got messy, not them. To make it a bit easier, I stirred the canned food to make it more smushy, like a thick gruel. It is surprising how much energy it takes to eat solid food, especially when you're used to sucking. Some also took to having it given to them with a spoon, that worked well. One super stubborn kitten had to have it literally stuffed into his mouth at first. But if you read the other thread, you would have heard that story already.
I don't really just like leaving the food and letting them find it. You can have problems with the smaller kittens not getting enough food. I gave each of them their portion in a separate bowl and supervised the feeding to make sure there were no thieves. A little much probably, but everybody got their fair share. I never left them alone with food (once they get the hang of it, they eat in less than 10 minutes, at least mine do, and canned food gets bad pretty quickly).
I also never put the food near where the litter box is. Kittens are often messy with the litter box (they are getting the hang of things) and contaminated litter can be strewn everywhere (depsite frequent cleanings). If this becomes present in the food and the kittens eat it, or if they lick it off their own fur, they can develop coccidia and other lovely diseases. They have fragile little tummies. So solve that problem, I have them in a spare bathroom with a roman tub. The kittens ate outside the tub, inside of which was the litter box, and then were placed back inside when finished, so they could do their business.
I probably, however,
really overdid it in the precaution department.
Now that the teeth are completely settled in and stronger, I am working with them on hard food aka kibble. I want them to be adaptable when they are adopted. Some owners feed canned, some kibble, some a combination. I think it's important that the kitten should be exposed with all three methods so that whatever their new owner springs on them won't hurt them.
She would probably protest considerably. Then of course your reference to milk was entirely appropriate, and other people were making assumptions, as I did. I apologize. There are so many kitten threads floating about, that I'm getting pretty confused. 
