You could do some of the work at home...Changing cables and housing is simple, just have them cut the housing to the proper lengths. Bar tape is easy enough to get the hang of. You could buy 1 roll of cheap ($3) cloth tape just to get comfortable with the process, and once you have it down, put the desired tape on. Yes, they might've sold you a too-small bike, but if you can't/don't want to exchange it, just go for it. Plus, you might be able to argue the proce down a little because of it.