in the gas tank
Replacing the head gasket on any vehicle is a long and complicated process, however if you wish to see basic step-by-step instructions go to the related question on the right side of the page "How do you replace a head gasket?"
If it was removed then YES.
replace the heater core
There is only one way to replace the 1991 Storm head gasket. anything in the way of getting to the head has to be removed (intake, hoses, etc..) Then the valve cover and head will have to be removed to change the gasket.
In the rear mounted under the vehicle.
head gasket blown. reface the cylinder head and replace gasket. that should fix the problem
Buy the Service Manual and follow the instructions.
The 1991 Ford Tempo radiator plug is on the bottom of the radiator. The plug can be removed with a half inch ratchet.
I believe you want to drain the coolant, remove the top hose at the thermostat housing, remove the housing, replace the stat and gasket, reassemble fill with coolant and bleed the system.
Usually under the steering wheel covered up by plastic.
Between the intake manifold and the engine block; Dude, if you didn't already know that much about your car you shouldn't try to replace it by yourself. Get help.