if you only have a phone number1) Open your 1st facebook account and deactivate that account. To deactivate a facebook account go to Account Setting > Security > Deactivate Account. 2) Now logout from your 1st facebook account. 3) Open your 2nd facebook account. 4) Go to Account Setting. 5) Click on mobile tab and enter your mobile number followed with country code. 6) After sometime you will get a verification code on your mobile. Enter that code and save setting. 7) Now logout from your 2nd facebook account and activate your 1st facebook account