Well- it would be wasteful to throw it away.... so take a hack saw and cut a grove in it- and then just use a common bit. Make sure to put it on something that will have to be removed before very long-- and don't forget the red loctite.
Just have a Mandarin speaking friend call up the factory and have them send you the broken broach tool used to make it. I'm sure they still have it; may even still be in the machine.