Anyway. We went out yesterday after commencement and replaced the front tires. The back tires categorically didn't need it. Then, today, the headlamp lenses I had ordered arrived. With shipping, the pair of them (right headlight, right turn-signal) cost $108. Our local Honda dealer only had the headlight in stock and wanted $150 just for that piece. I figured it would be 30 or 45 minutes' work to pull out the lenses, swap in the new ones, and close everything up.
As usual, matters happened differently.
It's very easy to get the turn-signal lens out on a Civic LX. It has to be: you can't replace the bulb without pulling out the lens cover. The headlight assembly is rather more difficult. It's held in by four bolts (not very easily accessible), and after you've undone all four you find out that it's also stuck behind a bracket that you can't remove as long as the front bumper in place. Fortunately, the front bumper is trivially easy to remove: five screws on top and two bolts on the bottom. Then it was another 30 minutes of grumbling to swap the new lens into the housing and replace and readjust the aiming screws. Then it was time to close everything up. Elapsed time: 2 hours 10 minutes.
I figure this saved us quite a lot of money in parts (I did some looking around before I bought these: new Honda OEM parts can be expensive!) and labor. I also figure this ought to be worth a few more points toward my Guy Merit Badge. I think I'll stop short of taking an engine apart in the living room, though.
PS. Thanks, Dad, for the socket set. I've gotten quite a lot of mileage out of it.