1. Click the box in the top left (with your name, team lead, and level)
2. Click the button with a gear on it, toward the bottom left. In English, this is labeled "Misc".
3. Click the button with two gears on it. In English, this is labeled "Game settings".
4. Click the drop down box at the bottom left of the menu that appears. This should have options of English and something written in Chinese.