you can just go for it hun, there is no harm in a dairy free diet, calcium can be obtained from other sources or else a good supplement. You need 1200mg a day when bf'ing. If you google calcium contents of foods, there should be some charts available to help.
It is probably worth going soy free too, half of dairy intolerant babies have problems with soy, as the proteins are very similar. I definantly wouldn't replace cows milk with soy milk, go for oat, rice, coconut or almond milk.