Hard Mode Hammer Station
Hard Mode Hammer Station bosses are most challenging for a healer. DPS needs some positional awareness, but tank control of enemies is the second most important factor for success.
Boss Guide
DN-314 Tunneler
If your tank gets annihilated on this fight, they probably didn't get cleansed. The tunneling beam does increased damage for each stack of a debuff it applies to the tank. Have a healer cleanse this partway through the cast to reset the damage multiplier.
Avoiding the demolition droids is the same as story mode: strafe around and use knockback skills to get them out of the way while you fight the Tunneler
Vorgan the Volcano (and friends)
The tank has three bosses to hold threat on here. Take out the Sawbones first, the droid next, and finally Vorgan himself. The weaker bosses can use a protective shield to reduce their damage taken. As a DoT spec, I don't believe it lasts long enough to warrant setting up a DPS switch, but you can consider it in your strategy.
The droid has a flamethrower that should be pointed away from the group. You can interrupt it once you're fighting it. No new abilities are gained as each boss dies, so the fight gets easier as it goes on.