For historical reasons, the eclipse plugin belongs to Drools project. That is why you need to go to Drools download section to get it: http://www.jboss.org/drools/downloads
In that page you have a section for the "Eclipse update site" that you could use in eclipse to automatically download and install the plugin.
If you prefer to do it manually, the file you have to download (from the same page) is: Drools and jBPM tools
Inside the zip you download, there is a readme that instucts you in how to install the eclipse plugin.
Thanks a lot for the help! I really appreciate it!