To prevent unauthorized access, please select your own unique security code, and change it regularly.
Enter your mailbox. If you don't know how to enter your mailbox, click here for instructions.
When it says "Ready", press 16.
It will list options - select 1 for personal options.
Press 4 for Security Code.
Follow the prompts (code can be between 4 and 10 digits).
Press the * to quit custom options.