Let's say the AddOn is called CustomAddon. Then CustomAddon.txt tells the game which files to load. So you do not have to delete any. If there are any additional files they just won't be loaded. But if you want to keep it clean, just delete the whole CustomAddon folder which path should be something like "My Documents/Elder Scrolls Online/live/AddOns/CustomAddon".
If CustomAddon depends on other libraries you should keep them up to date too, repeating the update steps for each of them. They are listed in the CustomAddon.txt and should be each installed in their own separate AddOn folder like
- "My Documents/Elder Scrolls Online/live/AddOns/CustomLibrary1"
- "My Documents/Elder Scrolls Online/live/AddOns/CustomLibrary2"
- "My Documents/Elder Scrolls Online/live/AddOns/CustomLibrary3"
See
https://www.esoui.com/forums/faq.php..._howto_install