My 2 cents
Heres a simple solution, take a blm and a rdm for sure. The first wall is the toughest so have the rdm 2hr and spam stone or aero. Then you should have some melee, like mnk, the hundred fists would be great. but anyways have the blm solo the north wall while the others kill qirin. by the time the blm is done they will have the bombs, you can blow the next 2 walls or maybe get lucky and even the last one. but if your whole pt is together you can down the last wall in like 3mins. So ya its really really easy. as for the blm, use choke frost and drown, then bio. then spam Aero, and when the DoT wear recast. Simple^^ have fun