Don't know about barcons but I've changed brifters and I've changed brakes+cable+housing on my mtb and it's not difficult as such, just a little twiddly. The cable housing is maybe the most important, don't cut it too short, you want it to run in as straight a line as possible w/o sudden kinks, and when you cut it make neat straight cuts. Park Tools has a good mech site with good photos.