How do I get the glass off this ceiling fixture

Question

I have this light fixture in my bathroom, and need to replace the bulb. But I can’t get the glass dome off.

There are no threads between the glass and the plastic mount/base. And no externally visible clips or screws. I can pull the whole dome down, off the plastic base, by about an inch or so. Feels like it is mounted with a spring mechanism inside, because it resists and when I let go, snaps back up.

Tried with a little extra force but it won’t budge further than an inch. And the base has an inner rim which means I can’t get a good peek into the inner works.

Tried jiggling, rotating and even pushing up. No luck so far.

Any idea how this is supposed to work?

Answer 1

Three flat spring arms extend down from the base. They have bends so that they can hook the glass once it is fully in place. Pull the glass down a bit from one side only. Slide a butter knife around until you find one of the spring arms. Then either tug down or use the butter knife to push the spring inward while you tug.
When you re-install the glass, hook 2 of the springs into the glass and use your fingers to push the third arm in as you raise the glass dome.