I've been on the search lately for a 4R up in the northeast area and have found several "low milage" that when I checked carfax the numbers didn't match up or the the car vs the miles didn't add up. Go on youtube and you can find a ton of videos of people showing how easy it is to do.
https://www.youtube.com/watch?v=uq6SlyVE4zQ
https://www.youtube.com/watch?v=T0qjwWzs23s