How do I install Ruby plugin Eclipse Windows Indigo

Hello fellow members,
How do I install Ruby plugin Eclipse Windows Indigo?
I keep on having this error during installation. The error is: Cannot satisfy dependencies: From: Eclipse IDE for Java Developers 1.4.0.20110615-0550 (epp.package.java 1.4.0.20110615-0550)
To: org.eclipse.epp.package.java.feature.feature.group [1.4.0.20110615-0550]
What does this mean?
I'm on Windows 7 64 bit.
Thanks.
