I believe you need a modified disconnector (the hook-looking piece that is attached to the hammer assembly) that will engage with the trigger bar sooner. You may need a modded trigger bar, as well. I believe according to CajunGunWorks, you need to replace both the trigger and disconnector. And I think they need to be fitted to the gun.
I think the CZ parts work, but cannot confirm from any personal experience. Probably best to email CGW, who seems to be the go-to for upgrades for these guns.