http://www.digitalfires.com/rekeying/lock_key_an.jpgSee where it says there's a retaining pin? In some wafer locks that wafer exists, usually after an empty chamber or a wider gapped area past the last waver the key would use. Reach back there with a hook or key extractor, and push down on it (or up, depending).
If your lock has that fella, just move it and tug and the plug will come out. It may take some play however, the last one I did I had to use a hook to hit the retainer and a key extractor to pull out the plug.
Once again, provided you have that type of wafer lock.
