You can, but I don't think Apple would. Even if they would, it's literally a 10 minute job and is very easy, I have done it myself. There are instructions to do so that came with your computer and also many places online.
That's good to hear, that's what I'm goin to do when the price drops then on the flash drives, finally I have made my mind up whether to get the Air 11" or the Pro 13.3", the Pro it is.