The Nym's Factory Compound where you encounter the infamouse Bounty Hunter IG-88 is a very simple instance that will wipe your entire group in three seconds flat if you're not competely on your toes.
Our group, which was the first to complete it, consisted of 2 Jedi, 2 Bounty Hunters, 2 Medics, an Officer, and a Commando. Roughly half the group had at least partially statted armor and powerups. Half had just plain armor and standard Mustafar weapons. The Commando actually wore Rebel Crusader Armor. This guide will reflect a similarly built group.
Similarly to the Axkva Min encounter, tanking isn't a simple matter of standing toe to toe with a boss and holding aggro. The flame throwers and rockets fired by the various bosses do an amazing amount of damage in a short period of time. Jedi playing as tanks will want to keep moving and trading taunts. IG-88 in particular can erase you in 3 seconds or less if he gets locked onto you.
For entertainer buffs you will want full energy protection and whatever else suits your character and his abilities. Initially, since certain mobs do kinetic damage, we were using kinetic armor buffs as well, but I don't believe this is necessary.
The Beginning
After everyone has completed the pre-quests leading up to the Heroic (which is already detailed in another walkthrough), each member of the group will have to click on the Retina Scanner to individually enter the instance. This should be done swiftly, as things start happening as soon as the first character ports in.
The entrance to the factory, and the Retina Scanner, are guarded by elite level 90 protector droids. It may not be necessary to kill these. Running through the droids and incapping or dropping aggro at the entrance is sufficent (although murdering all the droids is fun, and good XP for the less than level 90s in the group).
Phase 1
In the first phase of the enounter, exploding CL90 Battle Droids will spawn from doorways in the corner of the retangular factory area. Before they begin spawning, place your Jedi and your Bounty Hunters directly in front of each door, so that each is blocked. As the droids spawn, they will explode on contact with the Jedi or Bounty Hunter, dealing minimal damage.
All other group members should proceed to the center of the factory area during this phase.
Phase 2
At the end of the first phase, CL90 Gold Boss Droidekas will spawn in place of the Battle Droids. There will be four of these initially. The Jedi and Bounty Hunters blocking the doors immediately aggro the Droidekas and drag them to the center of the factory area, where the remainder of the group is waiting.
That the Jedi and Bounty Hunters get aggro on the Droidekas is very important, as it keeps them from aggroing the Medic(s) and nuking them immediately.
As the initial four Droidekas are destroyed, four more Droidekas will spawn from the corners. Aggro should be picked up immediately by the tanks or damage dealers, and pull them into the center. This is important so everyone in the group in range of area heals.
Phase 3
After the last of the Droidekas is destroyed, the group should disperse to the edges of the factory area, clearing the middle. MSE droids will spawn and begin circling the instance. They are attackable and only CL1, but are invulnerable to attack. Moments later, 2 CL90 Gold Boss Battle Droids will spawn and move to the center of the factory.
These Battle Droids are equipped with extremely powerful flamethrowers, and use the MSE droids to target artillery barrages on you. Everyone must remain moving during this phase. Red crosshairs will appear at your feet, signalling that the MSE droids have marked you for a rocket attack. The DoT on the flamethrower hit is enough to erase three quarters of your health before you're even able to heal. Fortunately, you have a second or two to get out of the crosshairs before you're hit. Keep moving!
One tactic that has worked for us is choose one Battle Droid (usually the droid on the West side of the instance, but which one you choose is irrelevent) and have the medics trade Stasis on it while the rest of the group focues on nuking the remaining droid. This is a very difficult part where you will wipe if your medics aren't on top of their game.
Phase 4
When the last of the two Battle Droids has gone down, IG-88 himself will become attackable and move to the center of the factory. He's a CL90 Gold Boss, with powerful blaster and flamethrower attacks. He has approximately 525,000 health.
This is a good, old-fashioned slugfest. Your medic(s) should have time to get everyone rezzed and healed before IG-88 becomes "hot," so if all has gone well, you'll have your full group at full health.
Ranged attackers should fan out to the walls while the Jedi move in to attack. Hit IG-88 with everything you have, while the medic(s) keep the heals up. During the fight, several CL90 Droidekas will spawn from the corner entryways, but these are relatively easy to brush off. One of your Bounty Hunters or Commandos can take care of these while the remainder of the group focuses on IG-88.
Once IG-88 is defeated, all members of the group will receive a permanent +1 bonus to combat strikethru, as well as a Token for defeating the instance. Tokens can be saved up and used to purchase rewards at the Township of Aurilia. Additionally, IG-88 can be looted. In our case, I looted a "Dented IG Droid Head" which gives a random buff or debuff with a 30 minute cooldown. The buffs can range from an effect similar to BH shields, to healing 9k health and action. Debuffs can range from rooting or snaring you to increasing your probability of landing trivial hits. This particular loot was bio-link and tradable. IG-88 also drops the Juyo Lightsaber schematic.
Notes
You don't need the most statted-out characters to complete this instance, but you do need very good players who know their professions and can handle themselves under heavy fire. The rocket attacks in particular can be devastating. IG-88 glances for 1000 points of damage. Therefore, even if things appear to be well in order, the medic(s) should be on their toes for quick rezzes.
As for the medic(s), I recommend a full healing/rezzing template with all expertise into hate reduction and evasion, as well as stasis. It's important for the medics to be able to keep the tanks and shooters alive. Rez arms and Hero rings also come in handy if things go badly.
Good luck, and as I run this instance a few more times, I'll update the guide with waypoints and more particular information!
updated tactic for phase 3 the 2 battle droids is to all head to the right side of the field and move up and down there, your out of range of the other droids attack and u are inrange of the medic(s) to recive heals.