Clone this repository first.
To edit the plugin display name and other data, take a look at plugin.json.
Edit the name of the project itself by going into settings.gradle.
gradlew jar / ./gradlew jar
Output jar should be in build/libs.
Simply place the output jar from the step above in your server's config/mods directory and restart the server.
List your currently installed plugins/mods by running the mods command.