Hope you have started solid feeds. By one year a child should eat whatever is made at home.
Milk twice or thrice a day will be sufficient. Excess milk is not going to help your kid in any way.
You may breastfeed him till 2 years.
You may have to slowly reduce the frequency.
Many kids will not like the taste of other milk because they are so used to breast milk.
To wean him off the breast, first you may try to give expressed breast milk in a sippy cup/ with spoon.
Then you may mix cow`s milk/ formula milk with expressed breast milk and give in the sippy cup/ with spoon. Slowly you may reduce the amount of breast milk and then stop.
But this will not happen in a single day. It may take a couple of months.
Hope my answer helps you.