To change your mobile number, go to Me Tab > Buying Tab > My Account > My Profile > Phone > Edit.
Enter your password for verification.
Follow the onscreen instructions to change your phone number. For security purposes, you may be required to provide additional account information for verification.
After you have successfully verified your account, you can now key in your new mobile number. A verification code will be sent to your new phone number.
Enter the verification code and click on “Continue” to complete the process. Your mobile number should be changed successfully.
If you're still having a problem changing your number, click here to learn more.