How can I make a JAR file of groovy script

I have to integrate Groovy script in C# code, so I searched about the same and found out that I can do the same if I make the JAR file of the script and then use it in C#, but as of right now I don't know how can I make JAR of groovy, as Groovy also run on JVM so it must be possible to make its JAR. Any help will be appreciated