Finally, a usable set of instructions that work! You are a saint.
I am using these instructions with the Steam version of ESO on Linux Mint, and it is working perfectly.
For those that are doing the same, and have no idea where to find the AddOns folder, it is buried in a somewhat weird place. Try turning on "Show hidden files" and look for someplace like this:
~/.steam/steam/steamapps/compatdata/306130/pfx/drive_c/users/steamuser/My Documents/Elder Scrolls Online/live/AddOns
See you in Tamriel!