1. At Manage Profile page, go to Security, click "Expand".
2. Select Country Code and key in your NEW MOBILE NUMBER, thereafter, you will need to immediately click on the "Lost/Invalid mobile phone?".
3. Next, key in the last 4 digits of the old mobile number for verification before we resend tokens to your email.
4. Security Token is sent to your email once verification is done. Copy paste the token into Security Token form and click "Save". You have successfully changed your mobile phone number.
Note that verification is required in order to proceed.