Device security
Select
Menu
>
Tools
>
Settings
>
Security
>
Phone and SIM
.
You can modify the security settings for the PIN code, automatic lock, and SIM card change, and change codes and passwords.
Avoid using codes that are similar to emergency numbers to prevent accidental dialing of the emergency number.
Codes are shown as asterisks. When you change a code, enter the current code, then the new code twice.