I did cows milk in his weetabix from 10 months. Then I started offering cows milk in a cup during the day. I am now adding some cows milk with formula (1/3) in a bottle. Doing it very gradually, like I did from breast milk to formula. I got liquid multivits (pregnacare range) and add to his bedtime bottle x
I started by giving my little one his breakfast cereal with cows milk (started this early). Did half and half for both bottles at about 11 months, then all of morning bottle after about two weeks after that. At 1 we did both all cows milk. Now he just has one cup of milk before bed.