How to upgrade soldered-in RAM

If the headline has gotten your hopes up, owners of sleek but underbrained laptops, allow me to disappoint you immediately: Greg Davill, who accomplished the feat, is an electrical engineer with fabulous tools including an x-ray machine, an infrared preheater, a nice reworking station and an evident tolerance for harrowing precision desoldering work. And he seems to regret the experience, successful as it was.

I've now got an XPS13 with 16GB of memory. But next time I think I'll just buy the 16GB variant upfront.

He links to a similar project on Hackaday, upgrading the memory on a MacBook. The first paragraph:

Note: i stopped this project and sold the macbook. This has not been attempted and should only be read as entertainment and inspiration. Please research yourself!

Research thyself indeed. There is, all the same, video of the job being accomplished, embedded below. I like how the title is a declarative that ends in a question mark: "How to Upgrade RAM On MacBook Air?" like they suspect they broke a law of thermodynamics or something and can't quite settle themselves amid their crumbling epistemic framework.