Are you using the ESB server? If so, all you really need to do is to edit bin/run.conf and uncomment the line :
If you want the server to stop before you attach with the debugger, change suspend=n to suspend=y.
Then, inside Eclipse, set your breakpoint and choose "Run"->"Debug Configurations" or "Debug.." (depending on your version of Eclipse. Choose "Remote Java Application" and use 8787 as the port.
Here's an article that spells things out :
Thank you, that surely did the trick