J.F.
well i am not sure how BM works, did not breast feed, but with my daughter i started taking her off formula when she was 10 1/2 months, she also ate big people food, but i started with 2oz cow milk and 6 oz formula, then decreased the formula till it was all cows milk, and when it was all cows milk on her first bday, i threw away all bottles in the house, and she got a normal sippy. because if bottles are out of sight they are out of mind, and i did not give in, she had to use the sippy. just like potty training when the time came and she was ready all diapers were gone, and only normal undies.
good luck