If you don't already have an Eclipse Account, register
If you haven't already signed your Eclipse Contributor Agreement,
You'll need to set up a development environment with the
workspace provisioned to include the Git repositories of
the projects to which you wish to contribute.
The Eclipse Installer
makes this super easy. Many projects have Oomph project setups to automate the
setup process. Use the Eclipse Installer's
Advanced Mode menu item to switch to advanced mode and choose the project on the
second page of the wizard.
Some projects make it even easier to get started by providing
a setup configuration: