Please note - you need to be a registered developer to utilise these packs.
Next, grab the Editor Pack
You will either need to install the mono framework version 188.8.131.522 (click here to download), or to install the native Mac uploader once the Editor Pack has been installed. After you have installed Unity and the SineSpace editor pack linked above, click on the Space --> Tools --> Install --> Native Mac Uploader menu option. This process will take a little time, but should be completely automated and you will receive a message once the uploader has been successfully installed.