how do you remove the thermostat on a 3.1v6 1995 cutlass ciera

I think you may have 2 questions here. If you are changing out the coolant, you don't HAVE to change the thermostat to do it (but if it has been more than a few years its a good idea). Remember, do not work on a hot engine. Let it cool before doing any coolant/radiator work. To change the thermostat, locate the thermostat housing (usually on the top, front of the engine block and identified with the upper radiator hose connecting it to the radiator). Loosen the bolts holding it down and pull the housing away from the engine block (if you keep it elevated, you will not lose very much coolant). Remove the old thermostat, clean off all old gasket material from the block and the housing, install a new gasket and thermostat taking care that it is oriented in the correct flow direction (block to radiator) and retighten the housing bolts. Now, if you are also changing coolant, you will need to drain the entire cooling system to proceed. This cannot be done from the thermostat housing. Instead, look for a drain valve on the lower portion of the radiator. If it is there, remove the radiator cap and open the valve. If there is no valve, best way to drain the system is to loosen and remove one end of the lower radiator hose and remove the radiator cap. After the system drains, close the drain valve (or secure the radiator hose), empty the coolant reservaoir tank, and begin to fill the system with the recommended coolant. Once you have filled the radiator, start the engine and let it circulate water for about 10 seconds. Shut the engine off and again top off the radiator. Repeat this as many time as necessary to keep the radiator full to the cap level. Once done, replace the cap and fill the overflow reservoir to the "full cold" line on the side of it. Start the engine and let it come up to temperature. Then recheck that the coolant in the reservoir is at the full line. If not, top it off and tou are done.

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