Try going to Spax Downloads Page and then to the Krypton Dampers owners manual link. That should get the instructions, such as they are.
The black art bit for road use usually consists of setting the preload to give what looks like the right ride height then driving it and adjusting the damping till it feels about right. What feels right on the road is right: it's different for competition use and involves stopwatches! Also, for road use there is a fairly wide window of damper settings that work well or to put it another way, a one click change might make a particular bumpy corner slightly more controlled and comfortable but the next corner might not be quite as good as it was before! Once you have it working well then consider adjusting the preload, again for road use the damping might not need changed for a small preload change but it is worth going up and down a couple of clicks to see what happens to the feel on the road.
Don't be daunted by how vague it all sounds, the chances are that the damping is set at a fairly decent setting out of the box but do check what the setting is - you need to know where you are starting from.
Have fun and remember that a lot of the benefit of replacement shocks is that the uncontrolled free play before the damping kicks in is much reduced compared to the originals, they also tend to have much better bumpstops so the end of travel movement is better controlled and they are much less inclined to overheat too.