Finally did the job last night. It took me a couple hours to do, but overall I didn't have too many problems with it. I basically followed the procedure in the shop manual, but here are some observations I ran across:
1. Along with the tank, replace the pressure cap, overflow hose, coolant sensor O-ring, and any hoses/hose clamps that need to be changed. Except for the radiator hoses, mine were all original (and old). I didn't do the pressure cap, but I'll probably pick up a new one when I get the chance. My coolant was only a couple months old, so I reused it.
2. Removing the tank: unscrew the two bolts (one of them was a PITA to access) and pull up from the engine side. My rubber grommet was still in pretty good shape - just work it off the old tank and fit it back in the fender hole. Once you've got one end of the grommet in the hole, push the rest of it in and down and it should re-insert easily.
3. Coolant sensor: Re-used mine, after cleaning it off. I put a little silicone grease on the new o-ring, put it on the sensor, and fit the assembly into the new tank. Make sure the hinged part is on the bottom. To insert the sensor all the way, I took a wrench socket just big enough to fit around the plug and carefully put my weight on it until it seated.
4. Overflow hose: Mine was so brittle it came apart when I tried to pull it off the old tank. You'll probably want to remove the overflow tank when you're removing the hose. As mentioned previously, turn the wheel all the way to the left, then you can access the bolts for the lining. I think there are 8 of them, not all of which are easy to find. You don't have to remove the entire lining to access the overflow tank (I did, though). Three bolts/screws, then pull on the tank from the bottom mount.
5. When everything is all put back together, fill the tank slowly, it overflows fast.