Start by upgrading to a competition hammer (e.g. a CZC 10035 hammer which has much lower hammer hooks than the stock hammer), then consider installing a CZ 75 pre-B disconnector (for short reset, CZ part 10126) and a 13 lb hammer spring. These three items took my CZ 85 Combat down to a 2 lb 2 oz SA and a 6 lb 13 oz DA trigger pull with a very short, crisp release and a short reset. All these parts can be installed by a mechanically competent owner and there are lots of YouTube videos for support.