I have a 1991 190e 2.6 liter. I'm replacing the seals in my differential and ran into a problem. The cap screws holding the axle connecting flange look like what I'd expect a fine torx head to look like in that it has the same kind of teeth, only more and finer. What is the tool and where can I obtain one? Are there any other ideas as to how to remove these screws?

Thanks.