shooty. lots of shooty. dakka, more dakka and more dakka. just make sure there's something reasonably durable between your boyz and the humiez. pantodapoi works wonders, their choppas own.

Always throw in a handful of HA, and a kata or 2 to finish them off when you run out of shooty things. if it still doesn't work, tell everyone to WAAAGH!!! and hopefully the shooty would have killed enuf of them humiez to make them runz.