How to change Admin's name on Mac?
Change the name of your macOS user account and home folder.
User account name and home folder name must be same. Backup your important data before proceeding.
Renaming the home folder.
Logout the existing account and then login with a new administrator account ( you can create a new account). Open user folder on startup disk.
Without any spaces, rename the user’s home folder. Remember you won’t be able to rename the folder if you are using file sharing to share the Home Folder.
Now to rename an account, follow these steps while you are still logged out of the account you are renaming.
Apple Icon > System Preference > Users and Groups.
Enter the administrator name and password that you used to log in after clicking the lock icon. Click the user’s name you are renaming from the list on the left side and click Advance Option.
Change the Account Name which should match the new Home Folder name (should have no spaces). The name entered will appear in the home directory field (after /users/).
If you wanna change the full name update the Full Name Field. You can either choose the full name or maybe the account name while logging in to your MacBook.
Click Ok and then you have to restart your MacBook. Check if your old files and folders and the account is working properly after login by using the renamed account.
For more tips and tricks related to MacBook.