Thanks for downloading.
Using the installer you just downloaded, you can finish the installation in no time. Here is how:
Upload or copy yeager_install.php to the document root or a subfolder of your webserver. In case you are uploading via FTP please make sure to enable the binary mode before uploading the installer.
2. Check permissions
Make sure that the user the webserver is running as owns permissions to write into that folder.
Execute the installer script via your webbrowser (e.g. http://www.xyz.de/yeager_install.php) and follow the instructions.
For further information visit the forums and ask away, or consult the documentation.