You want your tank in at least 250+ unbuffed FR gear. Put a priest in each group and all they do is dispell, shammies and druids do the healing. Just pull him to Garr's room and form a circle and have the tank in the middle. Its really a easy fight if your MT has the FR. Start getting your MT the Dark iron gear ( i think thats whats its called)(the gear that players can make from thorium brotherhood faction). a few rings can some enchants and your tank will be well over 300+ unbuffed FR ( you will need it that high once ya hit rags)
good luck in there and if ya need more advice just let me know