This is a very common problem among toddlers. It is important to realise the more they drink at night, the more they will wake up, and the more they will want to drink!
It’s difficult to know what to suggest when I don’t have more details of what you have tried so far, but I will give you the solution that we generally try first: gradually dilute both bottles with water and also reduce the amount by about 25ml each night.
Try to get him to drink only water or very weak rooiblos tea during the night. Once you have diluted and reduced, your baby may reach a point where will protest and want more – and this is where you need to be firm and say, no more milk. You might need to rock him back to sleep or sit with him if he cries a lot. Be gentle and patient, but also consistent and firm. He doesn’t NEED bottles at night, he just WANTS them!