I encountered this same problem on a 2008 Legacy, replacing a rear wheel bearing. Use a three jaw gear puller. It'll pop it right out. I used a 3 lb hammer and beat the crap out of the hub, but it wouldn't budge. I mushroomed the tip, but the gear puller pushed the tip right out. I tried to grind the tip down, but couldn't get the nut back on, so I wound up having to buy a reman CV axle, too.