1988 Chevy Astro how do I replace the thermostat

LOCATION:
The thermostat is located inside a housing, which is attached to the to the front of the intake manifold.

REMOVAL:
Disconnect the negative battery cable for safety.
Place a catch pan under the radiator, open the drain c ock and drain the cooling system to a level below the thermostat housing.
Remove the thermostat housing-to-engine bolts or bolt and stud, as applicable,
Separate the housing from the manifold and carefully remove the thermostat.
Using a plastic scraper, clean the gasket mounting surfaces.

((Exploded view of the thermostat and housing assembly-4.3L (1996 VIN W) CSFI engine))

1.) Thermostat Housing
2.)Thermostat
3.) Intake Manifold
4.) Stud

INSTALLATION:
Place a 1/8 in. (3mm) bead of RTV sealant in the groove of the water outlet mating surface.
Place the thermostat in position, then install and secure the housing using a new gasket.
Tighten the thermostat housing-to-engine bolts or bolt and nut to 21 ft. lbs. (28 Nm).
Connect the battery cable, then properly refill and bleed the cooling system.
Run the engine and check for leaks.

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