Ryobi 18V One Charger?

Looking at this forum it appears there's an internal fuse in the charger and that could be the reason 2 of them have died on me. How do you get to the fuse? Pulling the feet off the bottom there are star bit screws but they are so shallow there is no way to get the screwdriver to grip them. Is there another way to get the green and black halves apart?