You definitely need to have this done pro. However, if you know how to properly adjust a headset, you can do most of this yourself and only have the shop cut the crown race seat and install the crown race. They may grumble, but they should definitely charge you less since they don't have to mess with your bike, just the fork. $40 is pretty reasonable for a fork prep and install, though, so maybe they weren't even going to prep it.
I'm assuming your old fork is trashed, which means you don't have to worry about the truly tough part, which is pulling the crown race off without damaging the carbon. My mechanical guru won't even do this with the park tool, he only trusts the $$$ hozan version. However, you need to let them do this as well, as knocking if off with a hammer is a bad plan.