How do you activate onstar using free state farm rewards pkg?

I just did it - have about 15 minutes available (probably not a good idea to do it while driving....). Just press the blue OnStar button. When the operator comes on, ask for the "Partner Rewards program". They transfer you to a "Rewards Assistant", and it is set up in a matter of minutes.

You do need to let your State Farm agent know you have activated it. But it is supposed to save you 10% on the insurance.