Since it's a regular addon, it's manually installed the same as every other addon would be.
2) Extract it to your
Perhaps your game is installed to one of:
C:\Program Files\World of Warcraft
C:\Program Files\World of Warcraft (x86)
.. and so you would extract the contents of your downloaded archive to something like:
C:\Program Files\World of Warcraft\Interface\AddOns
.. and so you would end up with the folder
C:\Program Files\World of Warcraft\Interface\AddOns\TidyBar
.. and inside it would have
TidyBar.lua and all the other files.
Configuration / Usage
Interface > Addons > TidyBarwill give a number of options.
/tidybarwill force an update.
Issues and suggestions
- Disable all addons and re-test before creating an issue.
- Search for your issue before creating an issue.
- Always report errors.
- There are several helpful addons to catch errors. Try something like TekErr.