Instructions to remove the Joomla files and database manually without Fantastico.

As always, back up all site files and databases first.

If you don’t know the name and user of the database it can be found in the configuration.php file in the root of the Joomla files.
(var $db = and var $user =)

Knowing the database name will come in handy when deleting the database using the cPanel MYSQL manager.

Only delete the database user if they are not associated with other databases. If unsure keep the user.

Remove the default Joomla directives from the Joomla root .htaccess file
(Other directives may have been added by cPanel and you might not want to lose them)

Delete the Joomla core files and folders listed below.
(there could be other files / folders created by third party extensions, but usually these are nested within the core folders).

administrator
cache
CHANGELOG.php
components
configuration.php
configuration.php-dist
COPYRIGHT.php
CREDITS.php
htaccess.txt
images
includes
index.php
index2.php
INSTALL.php
installation
language
libraries
LICENSE.php
LICENSES.php
logs
media
modules
plugins
robots.txt
templates
tmp
xmlrpc

Default Joomla 1.5 htaccess for reference:

##
# @version $Id: htaccess.txt 10492 2008-07-02 06:38:28Z ircmaxell $
# @package Joomla
# @copyright Copyright (C) 2005 – 2008 Open Source Matters. All rights reserved.
# @license http://www.gnu.org/copyleft/gpl.html GNU/GPL
# Joomla! is Free Software
##

#####################################################
# READ THIS COMPLETELY IF YOU CHOOSE TO USE THIS FILE
#
# The line just below this section: ‘Options +FollowSymLinks’ may cause problems
# with some server configurations. It is required for use of mod_rewrite, but may already
# be set by your server administrator in a way that dissallows changing it in
# your .htaccess file. If using it causes your server to error out, comment it out (add # to
# beginning of line), reload your site in your browser and test your sef url’s. If they work,
# it has been set by your server administrator and you do not need it set here.
#
#####################################################

## Can be commented out if causes errors, see notes above.
Options +FollowSymLinks

#
# mod_rewrite in use

RewriteEngine On

########## Begin – Rewrite rules to block out some common exploits
## If you experience problems on your site block out the operations listed below
## This attempts to block the most common type of exploit `attempts` to Joomla!
#
# Block out any script trying to set a mosConfig value through the URL
RewriteCond %{QUERY_STRING} mosConfig_[a-zA-Z_]{1,21}(=|\%3D) [OR]
# Block out any script trying to base64_encode crap to send via URL
RewriteCond %{QUERY_STRING} base64_encode.*\(.*\) [OR]
# Block out any script that includes a