The application you need for changing your iDevices root password is called Mobile Terminal. This program has many useful functions, but today we are focusing on changing passwords. There are two passwords that are recommended to be changed. One is the mobile user password, the other is the root.
Here are the steps: (it is assumed you have Mobile Terminal installed and launched)
1) Type: passwd
2) You will be prompted to enter a password, the default password for ALL iDevices is "alpine" (without quotes). Enter alpine and hit enter.
3) You will be prompted to enter a new password, use anything you'd like but be aware that a longer password with both alphanumeric and numeric characters is suggested for better security. When you type the new password, it will NOT be displayed as you type. Do not worry, it's on purpose!
4) You will be prompted to enter the new password again, do so.
5) There will be no message displayed to tell you it was successful, so just assume it worked if there are no errors.
Now we need to change the root password, as we just changed the mobile user password.
6) Type: login root
7) You will be prompted to enter a password, the default password is again "alpine" (without quotes). Enter alpine and hit enter.
8) You will be prompted to enter a new password, it can be the exact same password as for the mobile user account if you wish. Enter your new password twice just like before and that's it! You've successfully changed your mobile user and root passwords! Congrats
This blog consist of all my iPhone tweaks and research. I try to document things clearly enough that you can easily recreate the same results as I did, should you choose to do so. Please remember that any tutorials should be used at your own risk, as I can't guarantee compatibility in all cases. All information is for educational purposes only. Thank you for reading my blog and I hope it helps you create a more personal iOS user experience.