Use a little WD40 sprayed around the rubber base as they are probably stuck in there from age and then they just pull out of the hole in the back of the gauge. Those bulbs are a dual pin base and are a model #57 and need to be twisted half a turn to release them from their socket. No need for LED bulbs as they are good brightness wise on a 1982 model year.
What happened to the headlight high beam project??? That idiot light being burnt out or the bulb removed from its socket won't stop your high beam headlight from working. The PO sacrificed what exactly in you post for a working high beam?

Dead warning light has nothing to do with your high beam not working, you just have no warning light presently.
What happened to you picture of the rear of the headlight connector and where is the blue wire as part of that headlight circuit?? Have you fixed the high beam and is it now working and you just need to sort out the idiot light for the high beam??