Nevermind...I made a tool to get it adjusted. Note this mixture screw does have an o-ring on it. Since I can now remove the screw the US cleaning in this area will be better now too.
I was always told that I could tear up a German tank with a rubber hammer.
As for the initial adjustment, count the number of turns when removing until the thread hop. That way you can at least reset close to where it was previously before any fine tuning that might be needed. Forget about replacing the welch unless you have a way of cutting a new one and have a doming tool set. Also don't remove the welch over the idle bleed chamber as it is also not in the repair kit. It is a shame how poor the carburetor repair kit is in general but Kohler simply wanted us to buy replacement carburetors instead.