This quest is no longer heroic, but Kiw'the Il'zhe will still do tremendous damage at the beginning of the fight as he may cast Ice Comet, which causes quite a bit of damage.
Steps[]
Deliver a letter to Kwi'the Il'zhe in Maj'Dul. ( 122, 139, -26 ) Copy/waypoint 122, 139, -26
To get to Maj'Dul, take the magic carpet from the docks. When you hail Kwi'the, he will attack. The quest will update after you kill him.