Raise the front of your Chrysler Sebring with a jack and jack stands or wheel ramps. Loosen the drain plug on the bottom of the radiator, located on the driver's side. Drain the coolant into a container. Reuse the coolant later if it is relatively new and clean.
Follow the upper radiator hose to an elbow where it turns into the front of the engine. This is the thermostat housing. Remove the hose from the housing. Remove the three bolts on the housing and pull off.
Note the position of the old thermostat before removal. Install the new thermostat in exactly the same position, with the spring-end facing the engine. Clean any debris and residue from the inside of the housing cover.
Install the new gasket over the thermostat. Reattach thermostat housing cover and radiator hose. Fill radiator with reserve or new coolant.
Start your Sebring. Turn on the heater and blow at the highest setting. Allow the engine to get warm. Check for leaks.