Step 4: Now the backup process will start which will last for few seconds
and the backup file will be stored in the phone memory.
taking the backup, even if you uninstall and again install WhatsApp,
it will automatically ask for the option to retrieve the backup files
(messages/conversations) after the installation process.
there is another option where you can email any particular friends or
groups messages. You can get this option at Settings -> Chat
Settings -> Email Conversation