2 best ways to kill him in heroic is 1. have hunters pet kill adds , and then hunter res pet and do it again ,2. have the lock put the life draining thingy on the boss and have the lock take all adds  ( locks spell dmg is going up so his health gained per tick is also ) o and for both make sure ur healer understands they have to heal , this seems to b a issue with healers they think they can dps in fights