Clean data and uninstall the app from your Android, uninstall the app and then install again. WhatsApp you ask if you want to recover some of your history.
"WhatsApp automatically makes backups every day at 4 AM and stores them in the WhatsApp folder of your Android phone."
http://www.whatsapp.com/faq/en/android/20887921
Clean data and uninstall the app from your Android, uninstall the app and then install again. WhatsApp you ask if you want to recover some of your history.