I had to do a clean install of Eclipse today and found myself stuck with a dodgy plug-in (subversive). However, when I went to the Help menu, I did not find any option to uninstall software. IIRC, there was something along the lines of Manage configuration here where you could go to makes changes and uninstall plug-ins.
The only thing relevant in the Help menu was Check for updates and Install new software. Clicking the former immediately checked for updates and offered no other options. However the latter did offer a dialog box and there it was, sequestered towards the right hand bottom corner: an inconspicuous hyperlinked What is already installed? option which when clicked brought up a new dialog box with a host of new options. Under the Installed software tab was a list of all installed plug-ins and buttons below offering to update, uninstall or list properties of any selected plug-ins. Once located, uninstalling my offending plug-in was a breeze.
I don't know what the UI/UX/USUCK team were thinking when they came up with this gem. I expect that they have some warped reasoning - "we do not want you uninstalling plug-ins" oslt - behind the decision. But I fail to see any logic behind it.