Go right to SCT's website. You can download the latest firmware, and their latest canned tunes. As long as your friend flashed back the stock tune, the tuner should be unlocked. You are allowed to change cars 5 times before the tuner permanently freezes. They have all the info on their website.
I wouldn't use any tune made for another car specifically. I'm not an expert on this, but i have read a bit on their website.