Originally Posted by
Clawed
On the bottle cage bolt, find a sequential set of left handed drill bits. Start small and drill out in steps. The CCW twist of the drill will eventually bring out the remains of the bolt, usually before doing too much harm to the boss threads.
??? I know this is counter intuitive, but standard right hand (clockwise) bits are what should be used. The grooves in the bit are cut opposite the direction the bit turns; therefore even thought the bit is turning to the right, it will unscrew the stuck stud the direction the bit is cut.