How do i get DS 13 months to drink cows milk?

[fnm]

DS hates cows milk, he will have it on his cereal but refuses to drink it out of beaker or bottle.
We have tried it warm, cold, dialuted with water and have tried the formula milk for 'toddlers'. But he will not have any apart from his usual formula.

I did the same as Lola. Started graduallly adding a small amount of cow's milk to the formula and then gradually increasing the amount of cow's milk and decreasing the formula.