Plate dying

Cut off the dying parts and 1/4" into the "good" part

I would not cut it up, but I would move the coral to a good flow area of the sand where waste can be efficiently removed and food efficiently brought to it.

I don't mean extra feeding, I mean the food that naturally occurs in the water is what feeds it. Have you ever noticed how Coralline algae grows really well in a high flow area. That's because more nutrients are being brought to it there than in a slower water flow area.

Often it's the physical damage that occurred in a move that starts this issue. Coral flesh is cut by it's own skeleton when it bumps into the bag or the side of the bucket or the hands that handled it. Combine that with the stress of moving into different water, with possibly coral aleopathic chemicals it didn't have to deal with in the old tank. That starts it dieing back. Using new AC can be helpful to remove those aleopathic chemicals. Fungia like the sand so find a place on the sand that's darker than the place it came from and has good laminar flow to wash away waste and bring dissolved nutrients for feeding.

If the coral dies, leave it there because in time dozens of budding babies may start growing up from in between the skeleton ridges. 

Oh, and I'd handle the coral as little as possible from the start (Fungia are terribly susceptible to damage around the edges where even our gentle grasp cuts the flesh against the sharp radial ridges. I would use a turkey baster or large syringe to help the current blow off the deteriorating flesh.

That's a good link Reef'd Up. I remember you posted that before, soon after you joined utahreefs, before moving to Utah. I assume you will be attending meetings and becoming a member of the WMAS. I agree with many things MechEng99 said about how to help coral recover.

One of the things I've learned over about 15 years of growing coral for profit is that they want to live, are very resilient and will recover when left alone in a good environment. Unfortunately, too many hobbyists don't understand what a good environment is and immediately jump to medicate, treating the coral like a sick person in a sterile hospital, which too often makes things worse. I have never used a QT tank, prefering instead to keep my tanks as naturally healthy as possible.

Coral can recover and often will rapidly grow back over recently exposed skeleton. I will often use a toothbrush to clean the algae off of a skeleton so the coral has a chance to recolonize it. There is a difficulty in cutting away bare skeleton. First, the handling bothers the coral and second, cutting can go awry and the coral cracks up in unintentional directions. Using a saw gives control but is very irritating to an already stressed coral. IME, if old skeleton must be removed, it's often better to wait for a while, until the coral has stabilized. Oh, and often a coral will appear to be deteriorating further, when in fact it's stabilizing inward a bit from the outer edge of flesh that was already compromised, so don't worry if a little more flesh sloughs off. Within a few days that flesh will wash away and the new edge of flesh will look normal and start expanding outwards.

This is just 2 cents from an old timer.

I hate to see sick things in my tank, and I'm sure we all feel the need to DO something, but I must agree with the other comments made so far to leave the coral alone and try to give it the best possible water parameters without stressing it.

I introduced a tang once that brought ich into the tank.  I immediately set up a QT and medicated the fish as soon as I was sure that the issue was ich.  The QT only made the fish worse as it was more stressed by the medication and by being moved again to a tank that was much less favorable than the main display tank.  As soon as I saw that, I put the fish back in the main display tank, but it was too late and the fish died.  As a result of introducing the ich to the tank, my yellow tang, which had already been well established contracted ick and I was tempted to remove the fish, but instead I just kept a close eye on my water parameters and tried to keep the sandbed nice and clean and my tang pulled through.  Fish and corals are very sensitive to stress and my experience has shown that the less stress we apply to the fish, the more likely they are to recover when they are ill.

Wow, that is pretty cool.  Maybe the little protozoans just don't like garlic, or maybe they are vampires.