There is a pitcock valve on the bottom of the radiato. On the side facing the engine. It has a T shaped handle that you can unscrew to drain the radiator, and by default the engine block. You may have to use pliers to unscrew the plug, over time dirt and corrosion can make it dificult to loosen.
No
Usually a drain plug at bottom of radiator
about 1.5 to 2 gallons at 50/50
Chrysler recommends the green 3year coolant
the red coolant. the pink coolant is used for newer model.
add antifreeze
9 Quarts of 50/50 antifreeze
When you say, "AC coolant", I suspect that you're actually referring to AC refrigerant. Coolant (aka antifreeze) flows throughout the engine block & radiator, nothing to do with the AC sytem. The refrigerant is also know as R-134a Freon. The AC system capacity for your 2000 Olds Intrigue is 1.85 lbs. For proper charging, however, you'll need a set of gauges to properly charge the "high side" & the "low side". If you don't have gauges, I'd hire it out to an auto technician.
on the front of the oil pan the dumbest place i think
50% antifreeze/50% water is recommended for most conditions. Use of DEXCOOL-approved coolant is NOT recommended.
either remove skid plate or disconnect the bottom radiator hose and dump the coolant
Drain the radiator