Do the following to change your Cloud Sync account password:
1. Go to the Settings/Preferences of iStudiez Pro and uncheck the option to use the Cloud Sync service
2. Check the option back and tap/click "Sign In" button to sign into your account
3. Tap "i" button when on mobile or click "Forgot Password" when on a PC/Mac to reset your password
4. Follow the instructions from the email you will get to change the password.