If you don't have World of Warcraft: Mists of Pandaria 5.0.5 16135 client:
Create a new folder (this will be your game folder) and download there PandaWoW.zip
Extract all files in this folder
Launch PandaWoW.exe - Downloading and installing of basic game files will begin.
Register game account
Run the game through the previously downloaded and unpacked PandaWoW.exe
Note: At first start the game will a little freeze. Don't worry - it is a game files downloading process, just wait. The first login process takes about 10-30 minutes (according on the speed of your internet connection)
If you already have World of Warcraft: Mists of Pandaria 5.0.5 16135 (or higher) client:
Delete from game folder the next files: WoW.mfil, WoW.pfil, WoW.tfil, Wow.exe, Wow-64.exe, World of Warcraft Launcher.exe, MovieProxy.exe
Delete frome game dirrectory the next folders: Cache, Errors, Logs, WTF, Updates
It is best to remove all the files and folders except Data
Download PandaWoW.zip and extract all files from there to your game client folder (if required replacing the old)
Register game account
Run the game through the previously downloaded and unpacked PandaWoW.exe
Note: Write your login, but not email in Battle.Net Account Name field
Note: If your have any problems - write to the forum and we will help you.
Note: Also you can change the language of the game client on your own, but because server is Russian - everybody speaks in Russian in the chat
Have a nice game!
(P.S: Для русских поясняю - это инструкция для наших друзей из за кордона)