How do I replace the thermostat on my 1988 town car?

If you can tell me which engine your Town Car has, I can give you a more detailed walkthrough. The general procedure for replacing your thermostat starts with draining your coolant. There may be a drain plug on the bottom of the radiator that makes this easier. Based on the vintage of your car I would assume that the thermostat is behind the upper radiator hose. You’ll need to disconnect this hose on the engine side of the hose. The tube that the hose goes onto should have a few bolts holding it in place. This piece is your thermostat housing. When you remove the housing the thermostat will be sitting right there. You’ll likely have to clean up the pieces of old gasket material on the mating surfaces, before applying new gaskets. These should be supplied with your new thermostat. When installing the new thermostat you need to ensure that, if equipped, the bleeder valve (the little hole with a small piece of metal loosely hanging in it) is facing up. Be sure the thermostat is facing the same direction as the old one. After everything is hooked back up, refill your coolant, bleed the system, and check for leaks. Again, the amount and type of coolant and bleeding procedure will depend on the engine in your vehicle. I hope this helped. If you have any questions let me know. Good luck with your repairs!