...head gasket cover...

What would prompt a cluster-f*ck like that?

Do you think the valve cover gasket is bad? If so, then take the valve cover off and replace the gasket. You're not going to do anything to your engine by taking it off, replacing the gasket, and installing it.

DSMInduction was referring to the possibility that you might take it off and start your car, which clearly wasn't your intention.