NPC healers will spawn near the entrance, once they appear lead them to the wounded NPCs in the main room to the south.
The number of NPC healers spawned depends on the number of people participating in the Op. Three or four members will spawn two NPCs, where five or six will spawn three.
Have the NPC healers cure 7 out of 8 of the NPCs until their name changes to green and you complete the objective. Note: Some might need an enfeeble removed so be aware of that and change the NPC to heal that type of ailment, then back to curing.