I put in a request for Google to consider adding Jrox affiliate program with Google. They accepted the offer after Jrox contacted them YEAH! But here's the problem how do I make the below changes what files etc. I was referred back to Zen Cart for this information.

Answer:
(This is a copy and paste from Jrox forum:)
actually, we've been approved for tracking.

In order to use JAM with Google Checkout, you need to contact Google and ask them to whitelist your domain.

Secondly, you will need to edit the shopping cart you are using with Google Checkout to add some XML code in it:

http://code.google.com/apis/checkout/developer/checkout_pixel_tracking.html

QUESTION: what file exactly to edit? Im using zen cart

Answer:
this is actually done on the shopping cart side, not JAM.

once we get more information on this, we'll post it.