This retrofit is not substantially difficult depending on the vehicle you do it on. You should have good amount of technical ability (be able to understand wiring diagrams and work with 12V electrical systems) and a small amount of mechanical knowledge. I consider myself a fairly competent technician and I still got a lot of help doing this. Any part numbers I quote are for a UK spec Octavia in RHD, but should be identical for LHD (other than the headlights which are obviously different).
Prerequisites that I know of:
A BCM and CAN gateway which support xenon headlights. I cannot give a definitive list of part numbers which are compatible, but I know that BCM 1K0937087J and CAN gateway 1K0907951 are compatible.
Headlight washer jets - fitting this is a major job in itself and is outside the scope of this guide. UK MOT rules require all cars first used after 1 September 2009 with high intensity discharge headlights (any dipped beam light source with an output greater than 2000 lumen) to be fitted with a headlight cleaning system. See https://www.gov.uk/guidance/mot-inspection-manual-for-private-passenger-and-light-commercial-vehicles/4-lamps-reflectors-and-electrical-equipment#section-4-1-6
My car is an Elegance spec so had headlight washer jets fitted as standard, I believe the Scout is the same. This saved me a lot of work.
Quite a lot of time and money. The conversion cost me about £500 in total, but this heavily depends on how much you end up paying for the headlights, which are by far the most expensive parts of this conversion.
Parts required:
Nearside xenon headlight 1Z2941015G
Offside xenon headlight 1Z2941016G
If your headlights do not come with the ballast/driver and AFS slave module, the part numbers are 1Z0941641B and 7L6941329B respectively.
AFS master (range control module) 5M0907357C with software SW 0142 or later
Front suspension level sensor 1K0941274C
Rear suspension level sensor 1K0941273N
Fasteners for level sensors:
Front
1x M6x16mm bolt N10653201 with washer N0115477
1x M6 nyloc nut N10205802
Rear
5x M5x16mm bolts hex head N10430104
2x M5x3.8-6.5mm XL rivnuts N10601701
3x M5x0.5-3mm rivnuts N10597701
Dashboard dimmer switch without manual headlight range adjustment 1Z0941333A
Wiring loom - I used this one from Aliexpress which was designed for a mk6 Golf and required some adaptation as the pinout is not exactly the same as the Octavia. I also had the seller include an extra level sensor cable, as the Octavia uses two level sensors as opposed to the single one in the Golf.
Step 1 - install level sensors.
The front sensor is very easy to install. Take off the front left wheel and have a look at the subframe immediately behind the CV gaiter. There are two holes; the left one is a simple hole which is where the guide pin on the level sensor bracket goes, and the right hole is threaded, so put your M6x16mm bolt with washer in here. The bottom part of the sensor goes into more existing holes on the lower suspension arm, near the anti-roll bar. Make sure the arm on the level sensor is pointing outwards.
The rear sensor is a little more tricky as you have to get fully under the car. You also need to set 5 rivnuts in the left suspension - 2 in the upper arm, and 3 in the lower. The holes already exist, there should be 3 in a triangle at the bottom and 3 in a line at the top. You only need to set rivnuts in the outer 2 holes at the top. Unfortunately I forgot to take decent photos of mine, but you should get the idea. Mount the sensor using your M5x16mm bolts, once again making sure the sensor arm points outwards (it will not work if it's pointing inwards!)
Step 2 - install wiring.
This is probably the most time consuming part of the conversion. I tried to make mine as neat and OEM looking as possible. You will ultimately end up with wiring running between the following locations:
nearside headlight and centre of dashboard (behind climate control panel)
offside headlight and centre of dashboard
front level sensor and centre of dashboard
rear level sensor and centre of dashboard
centre of dashboard and CAN gateway (buried at the back behind the steering wheel)
centre of dashboard and cabin fuse box (or other suitable power source)
The looms for the headlights themselves have a short section which converts from the 10 pin halogen headlight connector to the 14 pin xenon connector, and also a CANBUS twisted pair and power wire for the AFS slave which needs to go into the cabin. I used some flexible conduit cable tied neatly from both headlights to near where the grommet in the bulkhead behind the battery is located as this is where I'd be passing the wiring into the car.
I got the wiring for the front level sensor into the engine bay through the hole that the brake pipe goes through.
The rear level sensor wiring enters the car through the same rubber grommet the ABS cable goes through, and runs down the passenger side of the car up to the front.
Once all the wiring is in the front, you need to get it into behind the climate control panel. This is pretty easy as you can just push it through the gap between the carpet and the plastic surround of the centre panel.