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 "Technical Contact Code", enter Technical user ID, password and click "Login"
After login, click "Option 1" (Change Password)
Enter password, reconfrim password and click "Change" to confirm your change
Make sure you comply with .my Domain Registry password rule