This seems like a trivial task, but I can't find an option to cleanly de-install the ADT from my Eclipse installation. Of course, I could just delete the folder of the SDK, but this just throws errors when starting up Eclipse the next time. The reason I'm asking is because my old ADT keeps throwing a wierd error (Failed to fetch URL https://dl-ssl.google.com/android/repository/addons_list.xml, reason: File not found) and I need a complete, fresh re-install.
Important: under Help -> about eclipse sdk -> installation details the uninstall button for all android plugins is greyed out
Answer
The only way to remove the ADT plugin from Eclipse is to go to Help > About Eclipse/About ADT > Installation Details.
Select a plug-in you want to uninstall, then click Uninstall... button at the bottom.
If you cannot remove ADT from this location, then your best option is probably to start fresh with a clean Eclipse install.