1996 Buick Regal Thermostat replacing

Oh fun fun! You have a good one. Here are the proper replacement steps.

Disconnect the negative battery cable.
Remove the air cleaner and duct assembly.
Partially drain the engine cooling system, into a suitable container, to a level below the thermostat.
Remove the engine torque strut bolt from the engine.
Disconnect the upper radiator hose from the housing.
Properly relieve the fuel system pressure.
Disconnect the fuel lines from the fuel rail.
Remove the heater hose bracket at the thermostat housing stud.
Disconnect the heater hose from the throttle body.
Unfasten the thermostat housing retaining bolts, then remove the housing.
Remove the thermostat. Remove and discard the gasket.

To install:

Thoroughly clean the gasket mating surfaces.
Position the thermostat, then install a new gasket.
Attach the thermostat housing to the inlet manifold. Coat the retaining bolts with RTV sealer before installing them. Tighten the bolts to 18 ft. Lbs. (25 Nm).
Connect the heater hose to the throttle body.
Install the heater hose bracket at the thermostat housing stud.
Connect the fuel lines to the fuel rails.
Attach the upper radiator hose to the thermostat housing.
Install the engine torque strut-to-engine bolt.
Install the air cleaner assembly, then connect the negative battery cable.
Refill the engine with the specified type and amount of engine coolant. Start the engine and check for coolant leaks.