Pull the shock absorber out vertically without turning for at least 1 cm to disengage the adjusting mechanism. As shown on the knob turn counter clockwise for firmer clockwise for softer.

1958 Koni Shocks For Jaguar Advertisement Flyer
How to adjust koni shocks. The first method is a simple collapse of the shock absorber to engage the adjuster. Remove the dust cover and expose the adjusting button figure 2. Adjustment procedure 26 28 30 series. Almost all koni externally adjustable dampers are quickly and easily adjusted by placing a koni knob on the adjuster tab that sticks out of the top mounting threading. Just got my new koni sports yellow and was trying to figure out how to adjust the rears. Anybody install a set of koni yellows recently.
According to the instructions you compress them fully then rota. Remove the dust cover and expose the adjusting button figure 2. Hold the damper body by hand where the piston rod emerges form the cylinder. Feeling kinda stupid here but directions video on the koni site are not very helpful. Do not use any device other than by hand to depress button. Keeping the shock absorber collapsed make 1 half turn 180 degrees to the right clockwise.
Some externally adjustable shocks use an adjuster window instead. In case of prior adjustment add the number of half the turns previously found. Push the button carefully by hand and hold it in that position figure 1 2. On the second design you have to extend the shock absorber remove a spacer collapse it adjust it to your. The total range is about 5 half turns. Hold the damper body by hand where the piston rod emerges from the cylinder.
Rebound adjustable the adjustment is made with the shock fully extended. Push the button carefully by hand and hold it in that position figure 1 2.