The freehub doesn't quite roll as smoothly as before. Pedalling back actually turns the wheel back if it's free spinning. So we thought we'd take the body off to clean it and see if anythings broken or not. But it won't come of the wheel. I believe it should pull off, but with all my strength it doesn't. Tapping it with a hammer from the other side also wasn't fruitful. What else can we try to get it off?