This documentation is not using the current rendering mechanism and is probably outdated. The extension maintainer should switch to the new system. Details on how to use the rendering mechanism can be found here.
The installation process of the extension is just as usal. You need to download and install the extension by the extension manager. The default settings in the extension manager will do for most cases.
If you have done the described steps above, you will need to add the static template on the page or pages you want to include into the optimisation process. Due this you can simply test the extension on a small page or page segment before you include it on the whole site, because the extension will simply do nothing without an included static template.