There are many alternatives for dairy. I myself like the soy products. I replace the milk, butter, cream, yogurt and even my bread is soy-based. There is cheese, called  ‘Zero Lactose’ and also milk is available in lactose free.There is almond milk or rice milk, which you’ll have to try for yourself.

But those are the obvious things you will look for and because it’s very depending on every individual how much lactose you can handle, it would be best to find that out first.Scrap all products from you menu containing lactose and then start adding bit by bit.