It's been a long time since I had to do this from scratch, and I don't know your setup, so please ask more questions if you get stuck. I'm probably missing some steps.
1. Open the project in your IDE of choice. I use
IntelliJ Community Edition, but Eclipse and others are fine as well. I haven't used Eclipse in over a decade, so I can't help with workflow there.
2. Find the main() function in the global/ package. In my stable branch, it's in global/Main.java. In other branches, it may be in global/Global.java.
3. Hit the play button next to the class header or main function. This should build and run things correctly. In IntelliJ it will also create a temporary build configuration for you, which you can save and edit for more permanent use.
If you want to build without running, one of the top menus should be called "Build", with a "Build Project" option. If you want to do without an IDE and run raw javac from the command line, I wish you luck.
Hope this helps/works at all!