Help with weaning kittens?

In my experience they don't drink much water until they transition to dry food. If all three are making a decent meal out of the canned food, I would start to discontinue the KMR. Leave the water around in a shallow bowl and they'll get to it when they're ready. If they figured out the canned food, they'll have no problem with water when they want it :) If you need to reassure yourself, you can feel their gums. They should be moist. If they're tacky or sticky, then they're not getting enough water. In that case, add some extra water to the canned food.