Neosophist wrote:lutorm wrote:bikemonkey wrote:You can get ones with interchangeable bits

Well, but all I have is a round hole now. Even if I could find a round bit, I doubt it would do much good...

If you want to get a bit brutal with it you can do what many people have done with good effect and that is to get a Torx (star bit) that slightly bigger than the hole you have and hammer it in then use that to get it out.
Torx bit! Brilliant! That'll be my next try.
I cut the back off the pin, got the pads out, and then gripped that. No success - the pin just twisted.
I also tried the bolt extractor. It just chewed up the hold I had drilled without budging the bolt. (The bolt material seems quiet soft...)
I guess next is to pull out the propane torch. I'm replacing the seals anyway.