Go to the download page and under the "Artifacts" section, click on your desired environment:
If you are going with the core, download the "lib" file:
For any other variant, download the "plugin" file:
Don't let the version confuse you, the screenshots were taken of the version "2.0.0-BETA-3", but it may be already another version as you download it.
After downloading the plugin, put the respective .jar-file into the plugins folder of your application.
For the core it's usually enough to put it in the same folder as the main application, but it may differ. Please check the installation instructions of the main app.