Air Bleed valve leaking!!!

2001 Concorde: I have coolant leaking around the air bleed valve. I had to remove the upper plenum to gain access to the rear two bolts on the bleed valve, then I realized that I still couln't remove the valve because it is connected to a metal tube that seems to be running under the intake manifold.
Is there an o-ring type gasket on the bleed valve housing?
What is the trick to removing the bleed valve to stop my leak?
Has anyone here done this before?

I just replaced this thing last Saturday. It's called a Coolant Outlet Connector. There is no replaceable o-ring. It's sold as a unit. You need to remove the upper intake manifold. I had never done this before, but it came off pretty easy. You nedd to disconnect all the electrical and vacuum connections. Remove the throttle & cruise control cables from the throttle body.Remove throttle cable bracket. Loosen the clamp on the air intake hose on the throttle body & push that back. Now you can loosen the intake manifold bolts(8). there is also a triangle shaped bracket under the throttle body, loosen the bolt at the top. Now you should be able to lift the intake off. Remove the 4 bols holding the COC. There is also a hose clamped onto the long tube running to the back. Remove that hose and it should slide out. You did say you already removed the radiator plenum, if not you will need to. Good luck!!