Rear Valve Cover Gasket

[Assasin]

I have a rear valve cover gasket leaking onto the exhaust manifold on a 92' nissan maxima SE. I see that the intake manifold, folds right over that valve cover. My question is, I see that the intake manifold has what looks like,....... freeze plugs??? By any chance,. is there any coolant flowing through that intake Manifold? And is there any difficulty in removing the components attached to the intake manifold?