How to install it?
If you mean instructions on how to load and activate the plugin in the engine, try taking a look at the official forum, as there are a great variety of tutorials that may help you: https://forums.rpgmakerweb.com/index.php
But if you mean instructions on how to use the plugin after installing it, you can read the documentation either in the Plugin Manager interface after loading the plugin, or by opening the file in a text editor and reading the help section (which is the same text that is displayed in the Plugin Manager interface).