Disconnect the battery ground terminal using a 10mm wrench or socket. It's located underneath the coolant reservoir:
Remove the top radiator hose at the engine using a pair of pliers to release the spring clamp, and then carefully pull the hose off of the steel fitting. Allow the coolant to drain into a catch pan while you remove the remaining hoses.
Release the bottom spring clamp for the bottom radiator hose and slide it off of the plastic fitting just like the top hose.
Remove the spring clamp on the heater return hose to the thermostat using the same pliers. Slide the hose back past the thermostat housing while being careful not to damage it.
Remove the two 12mm bolts from the thermostat housing to free it from the water inlet, and then remove it by pulling it straight off the water neck inlet.
Clean all the gasket surfaces with a scraper or wire brush and be sure that all of the old gasket material has been removed from around the two bolt holes in the thermostat housing, as well as the water neck inlet.
Place a new thermostat in the housing over the dowel pin and secure the thermostat with the two bolts that were removed. Use a socket and ratchet to tighten the bolts to 84 in-lb. Apply a thin coat of RTV sealant around the thermostat gasket mating surfaces before installing it. It's always a good idea to replace the spring clamps with worm gear type clamps in order to help eliminate the possibility of future hose leaks.
Reinstall all of the hoses and fill the radiator with a 50/50 mix of coolant and distilled water. Start the engine and turn on the heater to get the coolant flowing thru the heater core and hoses so the air can escape. If equipped, turn the heat temperature control knob to the full hot position. Wait until you feel the hot air blowing from the vents and add coolant to the radiator as necessary. Replace the radiator cap.
Reconnect the negative battery cable.
