if you take the forks and stem out, sometimes you can see the rivets inside the head tube. i've used a screwdriver to push them out enough where you can grab them with some vice grips without touching the badge.
i've also taken a flat bladed knife and very, very carefully stuck it behind the badge and worked them out. it depends on how tight they are. if they don't move, give up on this method. you'll rip the badge. but most of them come out pretty easy.
you can buy new pound-in rivets from a good hardware place, like an industrial fastener shop for about 10cents each. or if you're lucky, you can get them out and reuse them.