Before going to Step 1, make sure to start up ESO first if you've done a fresh installation of the game and then the game will automatically write an addon folder for you to use in your Documents filepath (PC/Mac)!
Step 1) Go to ESOUI's website and pick an addon, any addon you want!
Step 2) Download and Open the Compressed File (we highly recommend getting the WinRar program online for extraction/viewing these downloaded files)!
Step 4) If you were logged onto a character in ESO, just type /reloadui into the game chat and press enter! No need to restart the game! If you did this with the game not started up, you can access the Addons section on your Character Login screen after you log into ESO.
Step 5) Note that you will need to download certain files that are called "Libraries" for certain addons to function. These Libraries can be found on ESOUI's website as well alongside addon files.
Step 6) As a final check after installing an addon and checking in the game, make sure to allow "Out of Date Addons" as outdated addons (so long as they're not severely outdated) still work. Some addon developers do not bother updating addons or their version names unless there's a drastic change to the API.
If you want to get rid of select addons, all you need to do is simply delete the addon(s) from the Addons folder in your Documents!
Just like with the manual installation of addons, make sure you have an Addons folder in your Documents>ElderScrollsOnline>Live directory by starting the game if it's a fresh installation.
Step 1) Go to Minion's website and download the Minion client.
Step 2) After installing the Minion client, you need to make sure to let it scan all your drives. This is the #1 mistake a lot of people make. It makes sense that you should only let it scan the drive ESO is located in but doing so can lead to a Minion error.
Step 3) Unlike the manual installation, Minion searches ESOUI for you and you can simply download addons without WinRar or click and dragging files. Basically the Minion client automates everything for you including being able to update all your addons with one click.
Step 4) You also however need to make sure the required Libraries files are still downloaded through Minion for certain addons to function.
Step 5) As a final check after installing an addon and checking in the game, make sure to allow "Out of Date Addons" as outdated addons (so long as they're not severely outdated) still work. Some addon developers do not bother updating addons or their version names unless there's a drastic change to the API.
And that's it! For more information, refer to the video above.