How to change whatsapp mobile number

Here is the basic tips to change your whatsapp number and inform your all friend in whatsapp regarding your new whatsapp number.As we know sometime we change our mobile number and that time we also need to change our whatsapp number. But what if you want all of your contact to inform that your changed your number? And even the group you joined in whatsapp? 

Click on Settings -> Account -> Change Number. Here you need to enter your old number as well as new number. Then you will receive the verification code in your new number. After that your number will be changed.