**SOLVED**  I can't figure it out and i feel super dumb.

You have to use XLN installer. Input your code that you have C3.  Also, make sure you select other/unknown for the store type.  You will see 3 "deals" come up - an ADPak deal (pick 3 ADPaks), a MidiPak deal (pick 3 midi Packs) and a kit piece deal (pick 3 kit pieces).
 
The code is case and format sensitive.

what i was missing:  even if you have it installed already, you have to reinstall it to get the goodies.  
the good news is that the reinstall is lightning fast.
genius putting those videos there to watch while goodies install.
more videos, please.

James, once you sign into xln as dave mentioned above and select your goodies, that's it... you don't have to download or authorize or whatever; somehow their magic just makes them all appear and you'll find them within AD2's browser/interface...
 
I went through the same "huh?" quandry back in the AD1 days with early sonar X... and emailed them... complaining... and found everything was already there... it's magic... enjoy it...

I didn't get "Input your code that you have C3"

When you log into the XLN installer, you will see the option to register a product.  Select that and you will be given a place to enter your code.  Note, you need to select other/not sure for the answer to the question "where did you get this product?"
 
The code you will enter is the one found in Command Center.  I think it can also be found in your Cakewalk Account.

Thanks the key was "Other/Not sure."