How to install addons to World of Warcraft without Curse Client!
World of Warcraft (fully updated)
1. Find the addon that you wish to install from a trusted addon website (i.e. Curse.com)
2. Download the addon and open via winrar
3. extract files to the desktop (its is best to manually install them)
4. Click start > my computer > Local Disk > Program files > World of Warcraft > Interface
it is not necessary to open the addon folder
5. More ALL of the folders that were extracted to the desktop into the addon folder
6. Open World of warcraft > login. in the bottom left corner there should now be a addon button
make sure load out of date addons is checked.
Hope this helped