BRNO ZKK 600

I wonder if anybody here remembers these rifles with that odd shaped stick-like single set trigger. I have not been able to figure out how to adjust that set trigger. I have the de Hass book and he goes into great detail on how to install that trigger, points out the parts, and mentions the adjusting screw but doesn't show it. I have other rifles with single set or double set triggers and adjusting them is fairly straight-forward. I can't find anything on this one that resembles an adjusting screw. This rifle is a good shooter but the un-set trigger is long and "gritty" and the set trigger is heavier than it should be. Any help here?