SHS-3321 - How to change the master PIN code

1. Unlock and open the door
2. Take the battery cover off
3. Press the [REG] button once to start the registration
4. Enter current master pin code (the factory PIN is 1234) + *
   • Success : Ding! Dong!
   • Failed : Ding-dong-ding-dong
5. Enter new master pin code(4-12 digits) + *
   • Success : Ding-dong-daeng
   • Failed : Ding-dong-ding-dong (PIN code must be 4 ~ 12 digits)