Question about returning thru "Advanced Exchange Policy"

So, I recently purchased a 2005fpw, which needed to be returned for a new one due to wavy black bars that scrolled horizontally up the screen. Now, I've recieved my replacement, which is definitely new and not refurbished, and was wondering how exactly I am to send the old one back.

They told me on the phone to send it back in the same box, but I'm not seeing a tag to slap on there or in the box to have it shipped back to them. Now, I know there's people here who've used this policy, multiple times at that, so how exactly do I handle said return?