Prerequisite: you must have ordered the plugin and have been issued a license key. Further instructions are provided in emails and communication.
Download the latest Varnish Nginx Plugin version from the download area, unpack the tarball, create a file called unixyvarnish.license with the license key copied within then run: python installvarnishnginx. You must NOT have anything installed. Your server must only have Apache.
1. tar -xzf VarnishNginx.unixy.net-2.4.0-elX.tar.zip # replace X from hereon with 5 or 6 if you're running CentOS5 or CentOS6 respectively (or CL5/CL6)
2. cd VarnishNginx.unixy.net-2.4.0-elX
3. python installvarnishnginx