I have done this and as the Doc said, it is a lot of work, in fact I think I would trade the car in for one with Xenons rather than do it again. Really happy with the results but not for the faint hearted.
To do a full OEM setup you need to replace the BCM, half the dash has to come out including the knee airbag. You need a new loom to go from the AFS controller to the Autoleveler, which you have to fit, a new loom from the AFS controller to the CAN controller, this is very tricky to get wires soldered on to as it is way back in the dash and a new loom from the AFS controller to each headlight.
Unless you can source a lot of the parts from Ebay etc then it will work out very expensive as well.
Here is the parts list I used

The hardest part was getting to the CAN controller and getting wires connected to the CANH and CANL pins.