One question mark is enough.

If you've bought them new they will have all necessary instructions with them. If they are second hand and do not have the instructions you will have to see what needs doing when you get them as different makes require different wiring.

I can't see them being difficult to install. It's usually just the halo rings you need to wire in. Everything else should work off the standard plugs.

The height adjustment is normally just a screw mechanism if they can't use the standard adjusters.

________________________________________

Rich