360 warranty sticker

Alright. So for anyone that doesn't know, best buy is doing up to $175 trade in credit when trading in a 360 towards an Xbox one, now my 360 is in great condition n has all its pieces, only problem is I've opened it multiple times and I have no warranty sticker.

Question, anyone e know where I can get an OEM untampered warranty sticker ?

Cause I know bestbuy won't touch it without one.

I got the S class Slim.