It would be to your advantage to buy a Haynes Manual as it would have just what you need to complete the job. They are specific to the car you own.
You do not, you have to replace it.
You need to CLEAN the intake up real good where the gaskets fit against it. Then make SURE that the intake is NOT PITTED, If intake is real smooth then there is no reason to replace it. Just replace the gaskets.
It is between $65-$85 for the gaskets.
The intake manifold are very bad about corroding a hole in them which means that you will have to replace it.
Probably a gasket leak. Could be the intake gaskets or the thermostat gasket.
Yes, you need to replace your intake gaskets.
Intake gaskets have failed.
bad vacuum hoses or leaking intake manifold gaskets.
you go to a mechanic
It is in the intake manifold close to the thermostat housing.
You will need to replace the intake gaskets to fix your problem. The HEAD GASKETS will not be your problem.
Have it pressure tested, the intake gaskets have probably failed.