Caught the other thread about specifc coords that Chillmaw wouldn't attack and couldn't get it to work.. Noticed a few others couldn't either.
Tried kiting him to Shadow Vault, and sure enough the guards will take em off your hands.
Some classes will likely have an easier time with this than others. Did it as a surv hunter and wasn't too bad. Probably common sense for kiters, but figured it might help a few out if they wanted to solo it or couldn't find help.
Pull him when he's closest to the path that leads up the Shadow Vault. Go light and haul ass up there. There's a pack of insta-spawn guards fighting scourge NPCs at the entrance. If you went light enough on threat, or can dump it, Chillmaw will get stuck on these NPCs. They have fairly low health (~12k) but they respawn instantly upon death.
If for any reason Chillmaw didn't get stuck on that set of NPCs or you couldn't drop him around there, just run him inside the inner part of Shadow Vault and the guards will aggro. Damage didn't seem to matter.. as long as I had tap, I got credit. Kill the 3 bombadier NPCs as they come out, and you're done.