For security, make double sure you’re logged in as an administrator user. nClick Users in System Preferences. Select the account you’d like to remove and click the trash-icon just below Login Options. If you choose Yes, will your home folder be deleted or saved?
Check to see whether the user account you’re going to remove is the only administrator account. If only one administrator account exists on the computer, removing it is not possible; instead, one of the other accounts should be made an administrator or a new administrator account should be created then deleted.
The Deleted Users folder, as the name implies, contains the contents of the Home folders of departed users. So unless they had any files or pictures you wanted to save, you might remove them.
Open the System Preferences program. Click the unlock symbol next to “Users Groups.” Select Guest User from the drop-down menu. Uncheck the box that says Allow guests to log in to this computer.
On the bottom left, click Users Groups. Select the padlock symbol. Enter your password. On the left side, select an administrator account, then use the minus sign at the bottom to remove it. Choose one of the options on the screen and then hit Delete User to delete it.
