Retrieving the monitor Vesa mount that has receded inside

I was changing my Mac LED display from being mounted on an arm back to its table-top foot/stand. I got the mount off OK, and vaguely remembered something about putting a small plastic card in the slot at the back of the monitor to release the mechanism, so I tried it: BIG MISTAKE! You shouldn't do that until you've reattached the foot. The mounting mechanism is spring-loaded and immediately snapped back inside the monitor's enclosure.

I saw one other post about this (discussion is now closed) where folks were saying if this has happened, it's a sure trip to the Apple Store Genius Bar and even for them it's nearly impossible. Oh contrare.

All you need are a couple of heavy-duty paper clips. Unbend the paperclip and use needle-nose pliers to thread one end of the paper clip through one of the 8 small holes that go through the mounting bar (inside the enclosure). Get a couple of paperclips in place and do your best to twist the ends back on themselves so they don't pull through. Get a good grip, and pull. The mounting bar will start to come up and then stop part-way. NOW is when you have to push the mechanism with the small plastic car - the mounting bar will release and you should be able to pull it the rest of the way out. (It's not easy - you'll likely need to grip the pulling end of the paper clips with some pliers).

I'll attach a couple of pictures.