To delete a user to your system bring up a terminal window and issue these commands:

To delete a user use deluser [username]

All this must be carried out as super user

To become a super user just type su - and enter the root password.
Ex.
[digerati@rh9 /]$su -
password:
[digerati@rh9 root]# userdel scrote

To delete the user and their home and all their stuff do:

[digerati@rh9 root]# userdel -r scrote


All done.