The biggest challenge when it comes to the iPhone X is parts availability. I checked a few suppliers to see what was available. I did find some rear camera lenses for the iPhone X over here. I haven't done this repair but I would think that it is similar to the iPhone 7/8. Either way, you'll be a bit of a trailblaser in this regard.
This repair is super simple. Just like every other iPhone camera replacement. Tools I recommend are the three major iPhone screwdrivers, an iSesamo and some tweezers. Patience is key.