Your local auto parts store should help you with that.
The thermostat is located on the passenger side of the engine. It you follow the top radiator hose to the engine, it is clamped to a housing. The thermostat is inside this housing. The housing is bolted to the engine block. There is a gasket to seal between the two parts. If you remove the housing, the thermostat just drops out.
right below your thermostat housing
on the water pump. follow the top hose from your radiator. it attaches to the block at the thermostat housing.
you might need a heater core
Just to the side of the thermostat housing.
It is under the housing that the upper radiator hose hooks to on the engine.
assuming it is a 5.0 L it is located on front side of motor just left of thermostat housing however it can also be found in the back of engine located in the supply line to heater core more than likely beside thermostat
Just follow the lower / bottom radiator hose to the engine and you will see where it clamps on a housing that has 3 bolts that hold it onto the water pump. The thermostat is inside of that housing.
Look in the removable housing at the engine end of the upper radiator hose
The heatercore is located on the passenger side under the dash. It is located on the left side of the blower fan. Remove the heater core housing which consists of 5-6 screws. Disconnect the two radiator lines under the hood that run into the firewall. There should only be one bracket holding the heater core in the housing. Remove and replace the heater core in the opposite order. Have a good one.
you might want to try flushing your radiator fluid. If it has been a while the corrosion in the water can will cause your thermostat to malfunction. also as a suggestion could be the blend door th actuator is on the heater housing at about knee level on right leg check that
Look in a removable housing at the engine end of the upper radiator hose