Go to the .my Domain Registry Domain modification page:
http://web.domainregistry.my:7002/Mynic-ViewController-context-root/faces/PB/UserLogin.jsp
Enter Domain name, select Domain extention and click modify
Select login as "Administrative Contact", enter administrative user ID, password and click "Login"
After login, click "Option 1" (Change Password)
Enter password, enter reconfirm password and click "Change"
Make sure your password comply to .my Domain Registry password rule