[MischievousOne]

You have to take off the IM (Intake manifold) first. If you have the extra money I would suggest buying a new rear valve cover gasket since the only way to replace that is to take off the IM anyway. While you're at it go ahead and buy new IM gaskets as well since reusing old ones isn't really recommended. After removing the IM you take off the water tubing and thermostat together.