
( Update May 2020: I’ve re-run through this whole process using Linux Mint 19.3 and have updated this blog post with new details. The only additional post-upgrade work I had to do was re-adding the Section "Device" bit to /usr/share/X11//nf as described below to get the brightness keys working again.)

( Update December 2020: I successfully upgraded from Linux Mint 19.3 to Linux Mint 20 by following the official Linux Mint instructions.


( Update December 2022: As suggested in the latest comments, this entire blog post is pretty much redundant now! Linux Mint 21.1 installs without a hitch, even using Cinnamon, and I have fully-functional brightness and sound keys straight out of the box.)
