How can I change my WhatsApp phone number on Android Tools

If you changed your phone number and kept your same phone, you can change your number within WhatsApp. Before proceeding, make sure that your new number is activated on your phone and that you can receive SMS messages and phone calls.

This process will: 
Delete the account associated with your old number, so your contacts will no longer see your old number in their lists of WhatsApp contacts. 
Migrate your account payment status, groups, profile, and chat history to the account with your new number.

Please follow these steps to change your account phone number: 
Go to WhatsApp > Menu Button > Settings > Account > Change Number. Enter your current WhatsApp phone number in the top box. Enter your new phone number in the lower box. Tap Done to continue. 

After successfully verifying your new number, your old number will be deleted from WhatsApp and your account information will be migrated to your new number.