I added and edited a fair amount of content in The Thunderbird Privacy Guide for Dummies!. Primarily i added info about an updater script for Linux that can be used to check for and download the newest version of the user.js from the HorlogeSkynet/thunderbird-user.js repository at GitHub. The script will also automatically append your user-overrides.js, if you have one, to the user.js.
I am not the original author of the script, who wrote it for updating the 'arkenfox' user.js for Firefox. I only adapted it so it would (should) work for Thunderbird. The script should be usable for Mac and Linux, though i can only test on Linux. There's a batch script for Windows in the 'arkenfox' repo that could be adapted to work with Thunderbird if anyone is so inclined.