Fairly simple, but a lot depends on how badly hacked about the headlight wiring loom is. I've seen some fairly woeful DIY HID installations! Nothing is irretrievable though; it may require a bit of soldering/heatshrink and maybe some bulb connectors. The worst case scenario is you'll need to get hold of a headlight/sidelight loom which is just over �30 from a dealer, which may actually be easier and quicker. TBH, for future reliability and ease of replacing bulbs it'll be well worth putting in the effort, even if you have to pay someone to do it.

__________________