I think you are thinking of the phrase  the other way around , which does essentially mean the opposite, but in a specific way. The specific nature of the other way around is that it means that doing what you say in the opposite direction is correct, not necessarily the exact opposite.
Once kittens reach 4 weeks of age, their mother usually begins to wean them off milk and onto solid foods. Because the weaning process can take up to six weeks, purchase a small amount of kitten milk replacement formula and mix it into your kitten's food during his first two weeks with you.
1 At about three to four weeks old, they can be offered milk replacer from a bowl and then small amounts of moistened kitten food four to six times a day.  Kittens from six to 12 weeks old should be fed four times a day as you gradually decrease their access to milk replacer.