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Apple’s support article HT1428: OS X: How to change user account name or home directory name, still refers to the old and buggy support article HT1528: Enabling and using the “root” user in Mac OS X. No one should ever need to enable the root user. This procedure is overly complex and buggy. If you really and truly need to act as the root user, use the Terminal and run the “sudo” command.

Here is a better procedure for changing a user account short name that does not require the root user:

Create a new Administrator account
Log in as the new Administrator account
Run Terminal.app and enter the following commands:
cd /Users
sudo mv oldshortname newshortname
Where “oldshortname” is your old user name and “newshortname” is the user name you want to change it to. Keep in mind that both oldshortname and newshortname must be all lowercase, with no spaces, and only contain letters or numbers.
The “sudo” command will prompt your for a password. Enter the password you used when creating the new Administrator account and press “enter”. Nothing will be echoed on the screen.
Use the Users & Groups pane (Accounts pane in Mac OS X v10.6.8 or earlier) in System Preferences to create a new user with the Account name or Short Name that you used in the previous step.
Click OK when “A folder in the Users folder already has the name ‘account name’. Would you like to use that folder as the Home folder for this user account?” appears. Note: This will correct the ownership of all files in the Home folder, and avoid permissions issues with the contents.
Use the Users & Groups pane (Accounts pane in Mac OS X v10.6.8 or earlier) in System Preferences to delete the old user
Choose Log Out from the Apple menu.
Log in as the newly created user. You should be able to access all of your original files (on the desktop, in Documents, and in the other folders of this Home).
You will now need to rebuild the Spotlight index for your home directory. Follow the instructions in Spotlight: How to re-index folders or volumes and add your new home directory to the Privacy list and then remove it. This will trigger Spotlight to reindex your home directory and restore functionality of All My Files.
After verifying that your data is as expected, you can delete the original user account via the Users & Groups pane (Accounts pane in Mac OS X v10.6.8 or earlier).

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https://discussions.apple.com/docs/DOC-3872

& for reference,

http://www.iclarified.com/entry/index.php?enid=4598

As for the “root user” problem you will encounter in the iclarified article, you can always enable root commands in terminal by typing “sudo -i”. Although, if you follow the first one you’ll be home free.

Now… Getting all that information and your UID back after you do that – Im still trying to figure that out right now, but I assume its essentially the same thing as the fix for this massive fuckup, albeit a modified terminal command with the correct chown -R command. Always use && before you type in commands like chown -R because && denominates the function thats typed after it to be run only if the first is successful.

be sure to reboot your system after you change your short name and long name before you do anything else. follow all on screen prompts before you use any terminal commands.

%% needs to be in front of chown -R, (thats a CAPTIAL “R”).

Anyone help me please?

Change user name to whatever you want.

Change your Macs Name to desired short name.
Via system preferences – sharing

Enable root user.

Log in as root user and change the name of the home folder to your short name.

Log out root and back in as user, right click on user name and change home directory to the home folder you renamed, it’ll say you have to restart, click ok.

Done

This changes Everything you could possibly want to change regarding naming your Mac and home folder. I recently purchased a Mac mini with tiger from a friend and took these steps to rename everything. Funnily enough did it by accident but can vouch that I’ve done it and it works