Just like any other tough, fast hammer unit. Lure with skinks (skirmishers or cohort) and flank with anything. Anvil&Hammer. Although this is quite hard with those knights. Blast them with magic, Spirit of the Forge really wreacks havoc on them. EotG's BA is bound to kill some. Those are the top 4 of killing enemy hammers. You do want to flank them, as they attacks you might recieve in return are reduced to 1 man+horse. While you also happen to get a nifty +1 CR bonus for it! Skinks are your very best friend here. So you want to kill the enemies support troops pretty soon (marauder cav, dogs) with your terradons/salamanders/chameleon skinks/more skinks/magic. Then you can move freely across the battlefield and lure/redirect anything you'd like. The classic hammer and anvil is ofcourse always a suggestion, but in practice it will not work as smoothly as in theory. Slann+Focused Rumination+Focus of mystery+metal lore...5 dice a spirit of the forge and watch the enemies melt. Don't forget your cupped hands of the old ones! EotG+Burning Alignment. Another classic way of dealing with knights. Ideally you would flank charge them, so you have impact hits+normal attacks+Burning Alignment. If you manage to fail right there, you were not going to win anyway! Do watch out for your skink priest when charging (anything, but especially chaos knights), he is quite....fragile. If they are frenzied it's not that hard. You can always rear charge them with something fast, light and cheap (skinks of any sort! terradons, sala's!) and then he has to pursue, thus pulling him out of position. This also accounts for when he's hatred. It usually takes some practice before you manage to manage the enemies' hammer units over and over, but in the end; you'll be able to. (at least most of the time!) Good luck! The Hunted
Spirit of the Forge, has NEVER failed me yet.. i think im up to about 35 dead Chaos Knights thanks to it.