One damsel down... I think another will die soon

[Bill S]

When adding corals you can basically add as many as you want at a time since they are not adding any bio-load to your system.

I would like to respectfully disagree with that statement...

As noted above, try some easier type corals first, like mushrooms and stars. I'd wait with them until your system tells you it can handle fish, other than damsels. Most are filter feeders and/or photosynthetic. And yes, you will have to tear your tank apart to get to them.