those are bulb holders. They have springy tangs along the circumference of the large base that contacts the gauge case.

use both thumbs to push them sideways, doesn't take much to release them.

use a colored marker and put a dot on one of them and on the case before removal so they don't get inverted.

 

Done, thank you. Dash section is free, and ready for stripping!

 

Yes, one of mine was split once I got it all out. Any ideas on regluing? Also, are they sealed units or can they be dismantled? Mine has what looks like tiny snail trails on the inside of the lens?