Downloading and installing an old version of the Android Development Toolkit (ADT)

If Eclipse is giving you grief and not allowing you to install an obsolete version of the Android ADT (example: installing ADT 15.0.1 in Eclipse 3.5, since later ADTs require Eclipse 3.6), here are some steps to help you install it:

1. Head over to http://developer.android.com/sdk/eclipse-adt.html#notes and pick which pick which version you want to use again.
2. Create your download url: http://dl.google.com/android/ADT-##.#.#.zip. Google uses the version number for the downloads, so if you need 15.0.1, your download would be http://dl.google.com/android/ADT-15.0.1.zip.
3. Install the new version as an archive (Help --> Install New Software ---> Add --> Archive)

This should get you back to developing!