The Joomla archive you just downloaded will have to be extracted to the /opt/lampp/htdocs/ folder. Open up console window and type sudo nautilus
Now go to the opt/lampp/lampp/htdocs and Create a folder called myjoomlasite.
Right click on folder and set permissions OWNER ROOT CREATE AND DELETE FILES, GROUP ROOT CREATE AND DELETE FILES Allowing executing - NO.
If you are not able to extract to this folder after changing the permissions.
Open the sharing tab and SHARE the folder. You should now be able to extract the archives contents to Myjoomlasite.
To see if your installation was successful so far, open browser window and type
http://localhost/myjoomlasite and press return. Hopefully you will be brought to the index.php page and be able to start setting up your joomla site. NB: Make sure no sql errors are displayed at the top of the page.
Το ίδιο χρειάστηκε να κάνω και για το php.ini