Extract gween.tgz to the document-root of your webserver.
Copy config.inc.php.dist to config.inc.php and change it according your needs.
Give the webserver full right on the cache directory.
It is recomended to define an rewrite rule for gween so it can be access by web without index.php and non-template files can be used in the component-direcotry.
RewriteEngine on RewriteRule ^($|.*\.comp|.*/)($|\?) index.php RewriteRule index.php - [L] RewriteRule (.*) COMP_PATH/$1
Set COMP_PATH to your compont path