The first location is in your Documents folder.
Finder > Go > Home > Documents
Delete the WoT alias folder (or World_of_Tanks folder in pre-2.x builds)
Next go to Finder > (while holding down the 'Options' key click) Library > Application Support
Delete the World of Tanks folder.
Then go back up a level, into the Preferences folder, and delete com.codeweavers.worldoftanks.plist
Then go back up a level, into Saved Application State, and delete com.codeweavers.worldoftanks.savedState
Then go back up a level, into Caches and delete com.codeweavers.worldoftanks folder
Finally go to your Applications folder and delete the World of Tanks app icon. Reboot your machine, login and visit http://worldoftanks.com/en/content/docs/update/ to download the latest version of WoT and run that new copy. It'll regenerate the data folders and redownload the game, getting you a working copy of WoT.