by FarmerFreak » 25 Feb 2010 8:21
This shouldn't be too difficult. I have an M3 key in knob cylinder in front of me. It has some kind of a black slide/clip (spring cap) that covers all the springs. It isn't too hard to slide that cap off and dump out the pins you don't want in the lock.
I don't have an M3 mortise cylinder in front of me. I think they are like the older Medecos, and they all used grub screws for each chamber. You'll need an allen wrench. Then simply take the screws out of the cambers you don't want any pins in and dump the pins out.
Have fun picking. Medeco locks can be quite challenging at first, but they're fun.