Weaning off breast feeding

Ladies my sister is having a hard time weaning my nephew off breast milk. He's lactose intolerant so he can't have anything dairy. Which means he can only have soy milk, almond milk, soy formula and coconut milk. I'm sure others but don't know what else. She even tried putting cereal in the milks but nope he throws a fit and won't drink it. He's 1 and a couple of months she doesn't know what else to try. Has this happened to anyone and do you have any ideas? He just doesn't like the milk he has to drink. If he drinks or eats anything dairy he breaks out on his body (eczema).