I suggest making backups of each original folder, just in case something fucks up.

Extract interface.rar
Place in main ../World of Warcraft folder

Extract Petrai.rar
Place in ../World of Warcraft/WTF/Account/<ACCOUNTNAME>/Uldum/ folder.

Extract SavedVariables.rar
Place in ../World of Warcraft/WTF/Account/<ACCOUNTNAME>/ folder.

Start game.

Your minimap might look all glowy and shit. If it does, right-click it, check "Use Global Profile", and click "Accept". Your UI will reload and it should look less glowy and more awesome.