you get a rare/ex bag, go up a big ass mountain, trade it to a place, go back to the NPC that gave you the bag, he gives you a key item, you go back up the mountain (note: Avoiding True sight mobs for Hedgehog bomb, Hagun is easy) and you go in, Hedgehog bomb requires atleast 2 75 BLM's.
Hagun you can go 6 man, (recommended). Our party set up is SAM, MNK, DNC or BLM (depends on what he wants) DRK, RNG, and Me (whm). It sounds simple and easy, but Hagun is kinda hard because you cant have people running around like chickens with their heads cut off cause they will pop 3-5 different mobs and will epic fail the run. so you have to make a train of people because you run over the NM that is covered underground to pop it. It has about 3-5 Place holders hidden around the map.
Hedgehog bomb is all about making it up the mountain without true sight aggro, or Jormy Aggro (big ass purple dragon that i wish was my pet for Dragoon) and facing away from the NMs inside the run because they can do a Job ability that can kill you in 10 seconds, its like a slow "Death" Spell.
Usually Hardcorespazz (My Epic ENM static leader + friend) takes the drops and puts em on AH because he is the only one rich enough to set em up. Once they sell He comes in person to give us the gil, or if he has the gil, he splits it at the end of the run and goes and sells the item. So instant cash sometimes. So yeah, its all fun, but if you dont know what you're doing you can easily mess it up