Step 1 - Go to the "Powertools" section and click "CMS(Joomla)" icon.
(see screenshot)

Step 2 - Choose destination directory (could be subdomain). Leave empty if you want to install directly in the main directory. Choose database, database user (the database should be created before installing the Joomla) and file owner. Further specify the site name which will appear in the CMS main page. Provide administartor name, email and password.
(see screenshot)

IMPORTANT: If you choose already used database, its content will be wiped out for the new content. Also note that Joomla takes 15MB of disk space!
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If you have more question regards this matter, please contact our
support team