High Scale KirnFollow

Hard to explain but easy to understand if you are familar with the dungeon layout. I am also assuming you have the group numbers or high level friend to take you because there are alot of mobs along the way that are dark blue to a level 70 player and you cannot get singles all of the time. They hit around 200-250.

Make your way to the "blasted doors" that lead into a winding tunnel.

Kill the 2 Ghosts guarding the door, beware of the wandering ratman and others and the wanderer construct in the tunnel itself. Med up just inside the tunnel and prepare for the close quarters battles and adds that you cannot avoid.

From inside the tunnel facing out, go into the building on your right. Make you way all the way up the stairs as high as you can go. Bring a Rogue or have the Sacred Key ready because Kirns door is locked.

I assume you know the quest and how to trigger the event. He does run at low health.