I'll answer my own question and post a "how to", assuming that others will experience this joy as well. This is far easier than taking it to the dealer. Of course this might happen again and not be a permanent fix...but I'll have to wait and see.
- Make sure your actually have a problem first! Unlock car at least 3 times, etc...
- First photo: insert a flat head screwdriver into the gap on the side of the flap (rearmost) to lever it open, making sure you're levering against the arm holding the cover and not the plastic cover itself. Also use a rag where the screwdriver will touch your car. Lever, but not that hard, it'll pop open
- Second photo: in my case the plunger separated from the door and was still in the hole (not pictured). A little wiggling and it popped out. If your plunger is still attached to the door, stop here. Grease it, hope it doesn't happen again.
- Third photo: To reattach the plunger, assuming it popped off the door, insert a screwdriver in the hole (arrow) to push down a tab. You can then slide the flap door towards the back of the car/towards you. For those of you who have had door handles fall off, this flap is attached the same way.
- Fourth photo: Using an M6 star driver (ideally), rotate the plunger mount counter clockwise. It'll then separate from the arm. Pull the rubber boot off, reattach the plunger (it just clicks on), and re-install the boot.
- Fifth photo: it's all back together, grease it, and it works. At least for now.