This wiki covers how to install LiteSpeed Web Server (LSWS) and LiteSpeed's Plesk Extension on a Plesk server. There are multiple ways to go about the installation. The wiki will only cover installing the Plesk Extension first and then installing LSWS from the extension.
This wiki assumes that you have a working Apache-Plesk setup. Latest version of Plesk may config Nginx as a reverse proxy server that stands between the Internet and Apache, please turn off nginx to make Apache your frontend web server following the Plesk Administrator's Guide instructions before you switch to LiteSpeed.