For GM I would hire Ron Hextall. Let him fire JC and either put Crawford behind the bench or DeBoer.
If Shaw and/or DeHann have to retire (I am hearing it is likely for both) then you have an opportunity to make FA changes as 8 Million in cap space becomes available.
I think you have to tell the new coach to bench Seabrook. He seemed willing to get traded when JC benched him and my guess is he would be willing to do so again. Eat half the contract and move him if you can or pay the expansion Seattle team a second-rounder to take him off your hands.
Currently, the moveable assets the Hawks have are Lehner (I would hope you try to resign him before doing that), Crow (Modified no trade), Maata, Smith (MNT), DeHaan (if he gets healthy), and the most likely to go Saad.
Simply put this is very likely to be a long and painful process.