this can be a bit of a git,i would soak the entire speedo drive in some penetrating oil or similar thn try to hold it with some good pliers and pull it out ,there is a small roll pin in the side in the side of the speedo drive that holds the pinion in that the cable is stcuk in bit its not easy to get out.you will ned to take the front wheel out enough to release the drive from the side of it.
adam bike doctor, February 2010