How to delete or remove user account in Ubuntu?
To delete the existing user accounts follow the steps given below.
Step 1: In the search box, enter as System Settings and press enter.
Step 2: In the System Settings window, select User Accounts.
Step 3: User Accounts window opens. Select the user account to be deleted and click -(minus) button.
-- If the user account is locked, then click Unlock button. In the pop-up, give the admin password to enable (minus/remove) icon.
Step 4: You will get an alert message asking whether to keep the records for home directory, mails and temporary files of the selected user account. Click "Delete Files" to delete all those items permanently or click "Keep Files" to keep the records.
User account will be deleted from the list as given in the image below.