How do I uninstall the legacy Java installed described here: https://support.apple.com/en-us/HT202912

I’m not at a Mac to check, but look in /System/Library/Java/JavaVirtualMachines/ or /Library/Java/JavaVirtualMachines/

Each subfolder in those are versions of Java. Delete the folder for Java 6 (or 1.6).

If if you don’t find anything there, I’ll post back later with where it can be found (when I get back to my Mac)