Forcibly Uninstalling Eclipse 3.5 Plugins
Solution 1:
One thing that you can try, is to go to your Eclipse directory, then "plugins" directory. There, remove the files and folders which are related to your SDK.
To find the concerned files, you should download the plugin file at this link. By checking the content of this archive, you will know exactly what files got installed, and what you should delete.
It's a bit extreme, and you can possibly prevent other things from working if you remove too much, so I recommend you to back this folder prior to doing so.
There might be some configurations remaining, and some unstable state of the plugin, instead of its complete removal, but it could be enough for you to be able to open Eclipse, and remove it properly.
Note that some plugins have configuration files installed in the workspace you use, in the .metadata/.plugins folder.