I make butter out of goats milk all the time.
I pasturize the milk, then put in a big pan overnight, then I skim off the cream and freeze it. When I have enough I made the butter. The first time it was warm weather and I used my mixer, I kept mixing and mixing, and it just got thick so I put it in the fridge, I posted on a goat site about it, one person told me to put it in the mixer cold from the fridge, and after about 10 seconds the buttermilk seperated and it went slosh all over! It was so cool!!!
It was good too!
It may depend on your goat, I have sanaans, and my one goat I milk gives alot of milk, it may take a while to get enough cream, but it is worth it! you can freeze the butter too.