Clone the repository and put the files in the document root (e.g. /var/www/html/)
Rename .env.example to .env
Create an empty database and provide your database information in .env
Visit /manage/install in your browser and setup a password and email
Done! That was ez right?
Make sure you have Apache with headers, rewrite and curl modules enabled (with a2enmod, apt-get curl+php-curl) and that .htaccess file is correctly uploaded and allowed in vhost config (AllowOverride All).