1996 Chrysler LHS how to fix a gasket that leaks coolant fr

I found a leak in my engine coolant system. It is found under the car behind the big almost centered pulley. Its drips like its crying and like its a gasket. It was heating up but found out it was leaking. I started to take apart but only ended up taking a piece that looks like a piston or cross or t. dont know what to do next. PLEASE HELP.