how to change admin name

You need to be extremely careful since one slight mistake may temporarily leave you unable to access the data and may leave you without an admin account to fix things. Here is an Apple article with the instructions:

Change the name of your macOS user account and home folder - Apple Support

Make sure to carefully read and understand everything in that article and perform each step in order as indicated. These forums are full of posts where users did not perform all of the steps correctly and lost access to an admin account and their data. It can be quite difficult to fix that mistake especially if you don't have a good backup first.

Make sure to have a good backup of the computer before attempting to make any changes so you can restore the system from the backup if something goes wrong.

You have been warned.

There is a process to allow an admin user to create a separate and new Admin account.

Perhaps that is worth looking into, and see what may be involved; and pay attention to

those items which later, may be cause of issues to be avoided. Big Sur is still evolving.

• Set up users, guests, and groups on Mac - Apple Support

https://support.apple.com/guide/mac-help/set-up-other-users-on-your-mac-mtusr001/mac

"Click the New Account pop-up menu, then choose a type of user. Administrator: An administrator

can add and manage other users, install apps, and change settings. The new user you create when

you first set up your Mac is an administrator. ~ Your Mac can have multiple administrators."

https://duckduckgo.com/?t=ffab&q=how+to+make+second+admin+user+account+macOS&ia=web

For troubleshooting, a second admin is also very helpful.

• Can't Log In to Your Mac? Create a New Admin Account | lifewire

https://www.lifewire.com/create-new-admin-account-for-login-issues-2259976

"A spare admin user account hasn't had changes made to its preference files.

It also doesn't contain any data beyond what macOS adds when the account

is created. After you have administrative access to your Mac, you can reset your

forgotten password and then log out and log back in with your regular account."

Once you have two admin accounts, it may be easier to change one name; to see what

happens. Trial run too, may be necessary; re-make backups before you change anything.

[Like anything, to assume a name-change, probably requires additional detailed changes.]

Good luck & happy trails!

🌻❄️🌿😷☃️🙈🤖😜

Make sure you have your data backed up so you don't lose any important files.

When acquiring a used computer it is always recommended to perform a clean install of the OS by first erasing the whole physical drive before installing the OS. This will destroy all data on the drive and provide you with a factory fresh OS. This is even more important for preowned Macs because a clean install will alert you to whether the Mac has a firmware lock enabled and/or is still being managed by the previous owner (both are bad things since you will have no way of disabling either one since you will be unable to prove to Apple that you are the legitimate owner). For an M1 Mac, you should not erase the whole physical drive because some volumes/partitions on the drive are required for the M1 Mac to boot (Apple has special instructions or you can "Restore" the firmware to wipe out everything).

A clean install of macOS will launch the Setup Assistant which will walk you through setting up the computer with your own user account and some other settings.

Generally if you have a 2010+ Intel Mac you can usually use Internet Recovery Mode (Command + Option + R) to boot to the latest online macOS installer that is supported on your Mac. However, Internet Recovery Mode doesn't always work as expected and does require a good network & Internet connection.

A better option would be to create a bootable macOS USB installer using the instructions in this Apple article (best to do this now while you can still boot into macOS on this Mac since Apple does not allow users to create the USB installers on just any system):

How to create a bootable installer for macOS - Apple Support

Which version of macOS installer you need depends on the exact model of your Mac and possibly the current OS. You can get this information by clicking the Apple menu and selecting "About This Mac". If you provide us the exact model and current OS, then we can advise you on which version of macOS to select.

Once booted to the macOS installer you will need to launch Disk Utility in order to erase the whole physical internal drive in preparation for the clean install of macOS. How you prepare the drive depends on the version of macOS being installed. Generally if you are installing macOS 10.11+ you will use Disk Utility to erase the whole physical drive as GUID partition and MacOS Extended (Journaled). However, if you are installing macOS 10.13+, then you will first need to click "View" within Disk Utility and select "Show All Devices" so that the physical drive appears on the left pane of Disk Utility. The physical drive is generally identified by the Make & Model of the drive such as "Apple SSD.....".

If you are installing macOS 10.6 to 10.10, then you need to prepare the drive by partitioning and formatting the whole physical drive as described in this article:

https://www.owcdigital.com/assets/support/support-formatting-and-migration/Mac_Formatting_6-10.pdf

After preparing the drive (erasing or partitioning), then you quit Disk Utility and select the "Reinstall macOS" item.

Here is an article that can help you to identify which versions of macOS are compatible with various Apple computers:

https://eshop.macsales.com/guides/Mac_OS_X_Compatibility

You will need to use either macOS 11.x Big Sur or macOS 12.x Monterey. Monterey was just released a week or so ago and users are reporting issues with many external USB drives not working plus some third party apps may not have an updated version to work with Monterey yet. So macOS 11.x Big Sur would be the safest option at least for another month or so.