Is it a huge job to remove the driver's side pedal board so I can get to the master cylinder? Will a '73 have a reset button on the master cylinder? I bled and replaced fluid but that red light is still on.

One more question: Is it difficult to identify the idle screw on a 2.0? Remove the air cleaner? Idle is running around 1500. I think it should be more like 1,000rpm correct?

Thanks!

You don't get to the master cylinder from the inside of the car. You access it from under the car or the drivers side wheel well.

Is there a cover plate or something for access?

Master is under the car.

Where under the car? How do you access it?

borrowed pic from a member here.
For the idle screw (air), you don’t need to remove anything. Go to
the passenger side and try to look for it by your left hand for the adjustment screw on the rear buttom of the air filter on the throttle body. Or maybe you have vacuum leak that makes the idle higher.
around 1,500 rpm when cold (AAR open) and around 850 to 1k rpm when warm (AAR closed)
Click to view attachment

remove the rack and pinion cover underneath the car that covers the steering rack. You can also bleed the brakes to reset

Like Andy said, you can reach it from the rear of the drivers front wheel. No need to remove anything for the reset button.