How to Change Mobile Number in WhatsApp

How to Change Mobile Number in WhatsApp :  

1. Open WhatsApp Settings.

2. Tap Account ▼ Change Number ▼ Next.

3. Enter your old phone number in the first field and your new phone number in the second field, both in full international format.

4. Tap Next. ...

5. Tap Done.

6. You'll then be prompted to register your new phone number.