My starting off point was this excellent post for performing this procedure on thumb safety models: http://czechpistols82792.yuku.com/topic/14688
However, be warned that decocker models have additional parts (including an extra spring) that add a level of complexity to the procedure. A small holed metal disc (fixing insert) retained in a recess in the left side of the frame (deep to the external hammer decocking lever controller) retains the sear pin. On decocker models, the sear pin is longer and not only goes thru the width of the ejector body, but also through both sides of the frame (unlike safety models where a shorter sear pin only goes through the width of the ejector body). There are extra parts for the decoker mechanism (an internal decocking lever and a decocking lever spring). The sear parts are under spring tension. At one point, two of the three small springs flew across the room and I was left with a mix of disassembled small parts (one spring was lost in the carpet for a very anxious hour). A CZ75 cut away diagram and exploded parts diagram helped me figure out the part placement. To reassemble, I had to use the mainspring plug pin as a slave pin, which allowed me to preassemble the sear mechanism parts outside of the frame. I don't see how it could be done otherwise.
The only thing I changed was the sear tip angle with a few passes of a honing stone. The single action trigger pull is much, much better and I am very pleased with the results. It is not nearly as good as a match M1911 trigger pull, but I don't think that is possible with the CZ75 design.
My main point is that the trigger action can be improved, but there are many pitfalls for the home gunsmith, so I can't recommend it.




