I have some new rivets that a Chrysler worker gave me but when it came time to move my VIN, I did what you just said. From the backside, look at the rivets. If they are hollow you can squeeze them to collapse the tube enough to push then out of the top. If they aren't hollow, because the piece of rivet is still in there, use a pin or tiny brad to knock it out from the top first. If you grind it off, it'll be short. If you do it this way, you could use a new rivet shaft on your old rosette head.
