Wheel bearing removal

I am trying to replace some rear wheel bearings and I can't seem to get the original bearings out. I've got Eric's book and based on the book I've tried heating up the area around the bearing to help release the bearing and I've been using an old screwdriver to try to knock one side out at a time. I can't get the screwdriver to bite decent enough on the edge of the bearing to make any progress. Any suggestions out there for this frustrated wanna be wrench :think:

In my frustration I posted this before doing a proper search. I've since attempted to delete this post but for some reason it keeps telling me I'm not authorized to delete the post.