It is rather easy.
First remove the turn signals. To do this, there is a retainer clip on the side of the turnsignal closest to the headlight. Use a flashlight and locate. Pop the clip outwards toward the fendert and it will pop out.
There are five bolts that hold in your existing headlight assembly. Three are easily visible on top, and one on each end at the bottom. Remove these, unplug the asseembly, and it comes right out.
Install your new ones in reverse order. ou will only use four to reinstall as the ZKW does not have a mounting hole on the top in the middle. The only wire not connected to the PNP harness is for your DDE. This can be tied into your parking lights or headlights whichever you so chose.
For more info, I'm sure Prez has a DIY in his sig. or umnitza's website has all kinds of video downloads that walk you through it.