Did this as a 43 lock solo, just deathcoil/fear spam, used the felhunter to nibble at him while I did drain life and the occasional shadowbolt. Just keep an eye on when the fear runs out, usually you can get another one off before he gets back into melee range. Rinse, repeat. Oh, and its a huge help if you have dark pact, as this tactic will run you low on mana pretty quick.