Uninstalling software is not the most straight forward thing to do in the 3.6 release of Eclipse.
Actually, it is a little bit like clicking 'start' to shutdown oin windows. To uninstall a plugin / feature you need to go to the install new software screen. On a Mac it's found by highlighting the help menu and selecting "Install New Software".
In the resulting window, there's a link which lets you view already installed software.
Clicking that link brings you to the installation details page which (assuming there are no dependency issues) lets you uninstall unwanted features.
Uninstall the unwanted software and restart Eclipse and you're good to go.