If a player logined our game via Facebook, he want to leave our game and delete the related data completely, he may do below steps:
1. Visit his facebook account and arrive "setting" page;
2. Find "Apps and Websites" option;
3. Find Crazybomb2(New MiniBattle) and click "Remove" button;
4. Click "View Removed Apps and Websites" button;
5. Find Crazybomb2(New MiniBattle) and Click "View" button;
6. Click "Send Requests".
CAUTION: Once above steps done and "Send Requests" pressed, all related data in game will been deleted and unrecoverable.