I have a 1996 Park Avenue with about 150,000 miles on it. I just changed the oil, spark plugs, transmission filter and fluid and air cleaner. I bought it used a few days ago, and I have heard that with that many miles it is good idea to flush the brake fluid to avoid ABS problems. ONCE in a while the ABS light does come on, but it is random. I had a 1993 PA Ultra that froze up the left front wheel caliper one evening in the winter and that was a bugger getting fixed. Ended up installing a different Anti-Lock braking system module in it, along with new rotor, disc, pads and calipers. The caliper got so hot I think it did damage to the seals in it and absolutely would not let fluid back out again once you applied brakes.
So, is it much of a chore at a brake shop? I consider brake work something for a professional to do. Too much at stake with brakes for me to mess with.