as said they are a straight swap. people take the motors out of the 1.2 standard headlight units, and put them onto the xenon units (Straight swap again) when these are plugged in you can then use the adjuster by the steering wheel to adjust the height.
when i fitted mine, i made sure the dash was set to 0, and then i manually adjusted the units (allen key on the adjustor/motor) on a flat surface facing a wall, to the correct level.
ive never had any problems with them, passed MOT fine too. as said, they are cracking down on xenon headlights, but to be honest as they are an actual xenon unit to start with, i.e factory on a 182, they arent that bothered. they are more so bothered about people putting HID/xenon kits into the normal headlight unit, which isnt designed for that type of light.