How to activate the free office on 8 inch Win8.1 tablets

My dad got a bundle deal at best buy today with a new Lenovo laptop and the mix 8 from Lenovo. I can't figure out how to activate or find the free office 2013. I know Microsoft is doing that for 8 inch tablets and it was advertised to have it at Best Buy.

Is it hidden? Is there an activation code, or did Best Buy forget to pre-install it?

Thanks in advance I know a bunch of you have gotten 8 inchers like the venue 8