Download the archive.
Upload the files from the archive to your server. Upload all the files in BINARY mode only.
Create the database.
Update config/config.php and change dbNAME, dbUSER, dbPASS and dbHOST, put your PageAddress, PageTitle, AdminMail and PartnersTitle (for your banner code at the partners page).
Create a confirm.txt file in the root of your script's directory and set 777 permissions for it if you want to log all automatic e-gold transactions.
Change the permissions of images and gfx directories and all files in them so they can be writable by the web server.
chmod -R 777 images gfx
or
chown -R <your_webserver_user_name>
images gfx
If you plan to use mode_rewrite check the .htaccess file and correct RewriteBase if necessary. For example, if your script is not in the DocumentRoot of your server, then change /. Suppose your script is accessed by:
http://your.domain.com/some_dir/hyip_script then substitute
RewriteBase /
with
RewriteBase /some_dir/hyip_script