BRAKE ROTOR TORX OR ALLEN REMOVAL

Thanks to Pete Myers for contributing to this FAQ!

Do not attempt to remove the rotor stay-screw with a star wrench; you will only get a lesson in frustration.

After soaking the screw with your favorite penetrating formula, apply a few well-placed taps to the screw using a medium punch and 3lb mallet or similarly heavy hammer. This rotor is almost seven years old, despite this the screw freed-up after only a few hits.

This screw is not torqued into the hub, it's merely there to hold the rotor in place and make it easier to mount the wheel without it shifting. You need only break the rust-bond with the punch and the screw will emerge cleanly. When replacing there is no need to torque it down and it cannot come out since the wheel will cover it.

Vincent Reynolds

If you don't want to ruin the rotor stay screw by putting punch marks all over it, do what I did which was to just go and buy the right torx impact
bit (assuming you have an impact driver) and make life easy for yourself. I think using a punch is an extremely crude way to get the screw out, and should only be done in an emergency or if it's unavoidable. It's definitely not the sign of a good mechanic.