Please help - need to identify/replace a bulb or bulb assembly (A body rallye dash AC/heater control)

I am hoping to revive this thread because I am stumped on how to replace this bulb. The original answer I got was helpful, in that I was able to identify the replacement bulb and realized the blue diffuser was removable. I ordered the replacement bulb and then got distracted by other things and am just now getting back to it.

So, yes, the diffuser came off, but I still have no clue how to extract the bulb and replace it, or if it can even be done without replacing the whole assembly.

This is what I am looking at after removing the diffuser:
IMG_0763.jpg

IMG_0765.jpg

The bulb is encased in a metal housing with no way that I can see to open it. My shop manual is missing the pages where bulb replacement might be covered (both my printed copy and the My Mopar copy are missing pages 8-62 and 8-63).

I can feel that the pigtail is spring-loaded and the bulb would have to go in from behind, but I feel like I am going to break it when I pull on the pigtail. I would swear that they intended the assembly that I am holding in my hand was intended to be replaced as a unit.

Someone must have solved this riddle before me in the almost 60 years since it was made. Please help if you can. Thanks!