To install Sapphire for Autodesk:

Step 1: Make sure that you have closed out of all host applications.

Step 2: Download the Sapphire v10 for Autodesk installer from here:

http://www.genarts.com/support/downloads/sapphire/autodesk

Note the Mac and Linux tabs.

Step 3: Run the installer and follow the prompts.

If you are looking on how to activate/license Sapphire, go here.