Go to My Menu → Settings → Personal/Security/Backup → Back up data to back up your data.
After the backup is complete, go to My Menu → Settings → Account Settings → Withdrawal to delete your Facebook account. If you cannot delete it, request account deletion through My Menu → Settings → Customer Service/Help → Bug report.
Sign up with another SNS account or e-mail address, excluding Facebook.
Refer to My Menu → Settings → Customer Service/Help → How to back up and restore, then select the backup file from step 1 to restore your data.
If restoration fails, do not reinstall the app. Send your usage records through My Menu → Settings → Customer Service/Help → Bug report so we can assist you.