Disconnect of gasket between housing and bucket any idea of how to attach it back on?

Open the hood of the impla and locate the thermostat housing. Find the largest hose at the top of your radiator, then follow it until it connects onto a portion of the Impala's engine block. The piece that to which the hose connects is the removable thermostat housing.

Use a jack to raise the Impala off the ground, then settle it down onto jack stands. Make sure the car is in park and the emergency brake is on.

Place a large container under the Impala's radiator. Drain the radiator into the bucket by loosening the clamp on the lower coolant hose with a flat-blade screwdriver, then removing the hose entirely so that the coolant flows into the bucket. Once the coolant stops flowing, set the bucket aside.

Use the screwdriver to loosen the clamp on the coolant hose connecting to the thermostat housing, then remove the hose from the housing completely. This will give you access to the bolts securing the housing to the Impala's engen block

Use a wrench or ratchet and sockets to remove the bolts securing the housing to the engine block, then set them aside somewhere where you will not lose them. Loosen and remove the thermostat housing to reveal the thermostat.

Make a careful note of how the thermostat is oriented toward the Impala's engine block. You must install the new thermostat in the exact same way as the old one is installed. Remove and discard the old thermostat.

Use a scraper tool or a razor blade to remove any remaining bits of thermostat gasket from the bottom of the thermostat housing and from the engine block. It is important to get all the remains off; otherwise the new gasket will not seal properly.

Apply a layer of gasket sealant to the bottom of the Impala's thermostat housing, then press the new gasket against the sealant so that it sticks and makes a good seal.

Install the new thermostat in the manner you noted in Step 6, then replace the thermostat housing and secure it down with the bolts. Reconnect the hoses you disconnected--making sure that the clamps are tightened down so no coolant leaks--and refill the Impala's radiator with the coolant you drained out earlier. Use your jack to lower the Impala back to the ground.

Park the car on a level surface, turn off the engine and let the engine cool a minimum of 2 hours before beginning to remove and replace the thermostat.

Place the bucket under the driver's side corner of the radiator beneath the radiator draincock (located on the bottom of the radiator). Remove the filler cap from the radiator.

Shape a large piece of aluminum foil to form a funnel or channel from beneath the draincock to the bucket, Pinch high side walls in the aluminum foil so it will direct the flowing coolant into the bucket and not allow any to spill on the ground or into the engine.

Turn the draincock clockwise to open it and drain the coolant from your radiator and hoses. Close the draincock when you have finished draining the system.

Locate the thermostat housing. The housing will be on the top of the engine; you can find it easily no matter what model year Saturn you have, by following the main hose coming from the radiator to the engine block. That hose will end at the thermostat housing and there will be one or two houses coming off the housing as well. Disconnect the hoses from the housing.

Using your socket set, remove the bolts holding the thermostat housing in place. Put the tip of your paint scraper between the housing and the engine block and pry up gently to remove the housing. Once the housing is free, remove the gasket that was between the housing and the block. If necessary, use the paint scraper to scrape off any old gasket that is stuck to the metal.

Pull the old thermostat from its seat. The thermostat has a circular steel top with what looks like a raised handle. Simply lift the old thermostat out and place the new one into position.

Lay your new thermostat housing gasket into place and re-install the housing. Tighten the bolts down. Re-connect the hoses and refill your radiator with new coolan