I just got my ring from kirn today. He is popping in the right spot as advertised. I was using the map I got off of the Shamans Crucibel forums here - http://forums.interealms.com/shaman/showthread.php?threadid=16046
However a few things to go over if your planning on raiding. We did this today wiht 60 shm / cleric / enc, 61 mage, 53 mage, 55 druid and 65 paladin/druid. An odd combo indeed. Anyway key things to note. The constructs are basically unslowable, old constructs are immune and destroyed are very, very hard to slow, even if you land tash and malo. I would say your best bet is to simply have a paladin tank with stuns for aggro, and nuke them to death. The same goes for gargoyles, somewhat easier to slow but basically better to just nuke them to peices. Also, don't let your chanters try to mez either of these...the aggro will be fast and fairly brutal.
On the flip side the ghosts of the old city and the ratmen guards are fairly easy to malo/slow. They can also be mezzed. Hence my suggestion is to make sure you raid force always concentrates on constructs/gargoyles while mezzing the ghosts / ratmen. Ghosts dont' CH, but they do do a 20-30% heal, so be sure you keep them mezzed and stunned or it'll get aggrivating.
Now, when your get to the blasted gate and the large tower building is where things can get hairy. I heavily suggest that you pull to the blasted gate to start with, then start moving your forces in room by room as you clear infront of you. Clear surrounding rooms if there are any, as wanderes and wall aggro will bring adds otherwise. Expect adds in any case, cause there will be some.
Kirn is on the top floor, and while the maps are hard to read you can just hug the right hand side of the building, going up each flight of stairs as you find them. You will pass the enchanter epic person on the 'lowest' floor with the keeper of the tombs near the center. Kirn is about 3 flights up from there, and you will know when you reach the top because the room has large windows looking across to the other side of the building. Kirn will not be KOS, so pull everything from his room and from the room across from you, then hand in and pull Kirn or fight him in his room.
The key for kirn drops off the Old Construct i believe, which you will probably encounter on the way, otherwise bring a rogue to pick the door. The key is also tradeable, so you might be able to buy it in the bazaar.
I imagine this can be done by a group of 60+'s or 2 groups or more of 55+'s. Bring enough nukers and at least 2 tanks to handle the above mentioned problems.
Hope this helps.