To make the third boss easy have your MT kite the boss to a fishtank.  He always uses the nearest one and kiting him over there puts your melee in easy range of the fishtank.  Then have MT send a raid warning (or announce in vent) when the boss starts to use the fishtank (he'll see the boss' target change).  Your healer should stay on the MT (especially in Heroic), but everyone else, including the MT, should blow out all the stops taking down the fishtank things so save your CD's for the fishtanks.  If he never enrages he's easy.  If he gets enraged he will kill your MT in a few shots as it increases his dmg by 75% and his melee speed by 100%.  Fortunately no one but the MT should even take damage, so it is easier to heal than the boglord pulls at the start of the instance, lol.

Best of luck!