First off, a big thanks to CirrusSR22 for the initial write-up, and to the others who posted as well. This was my first major project on my '98 ti and the information was invaluable.
Now that I've finished this project I thought I'd share my experience in the hope that it helps others. I initially decided to do this job because my thermostat was stuck open, but I also wanted replace the plastic connector pipes and radiator before something bad happened. My car has about 98K miles on it.
Tools A good 1/4-inch socket set is essential. Gear wrenches are nice. And I had to make my own water pump puller too.
Head Connector Pipe Yeah, this is a difficult little bugger. I was able to remove it myself, but installation was another matter--my hands are just too big. This is where a lovely and talented assistant can be big help. I talked my wife into laying on a board placed on top of the engine. She was able to reach behind the head get the connector bolts started--I pre-connected the hoses. If you've been waiting for reason to buy a set of metric Gear Wrenches, now's the time. A 12-mm gear wrench made it a lot easier to tighten the top bolt.
Water Pump When I tried to use the extra bolt holes to remove the water pump, the top part of the flange broke and then I discovered that the head of the bolt wouldn't clear the water pump housing on the bottom of my pump. Damn, the water pump didn't want to give up without a fight. I ended up making my own puller to get the water pump out. I kinda enjoy challenges like this.
Broken water pump flange. 
I welded some nuts on to a piece of 1/8 plate and cut a notch in the plate so fit over the pump shaft. I put some shims between the bolts and the timing chain cover so I wouldn't damage it. However,my first attempt at a puller wasn't strong enough. 
I reinforced puller with a piece of 1 inch square tube. The pump popped right out. 
Reassembly I made some goofs that really cost me a lot of time.
I didn't use any lube on the connector O-rings; I should have. When I filled the engine with coolant, the block connector started leaking because the O-ring didn't seat. The 12 V battery cable messed with me too; I managed to put everything together the first time without connecting it to the starter. Doh! Oh-well, I was going to have to remove the lower intake anyway to deal with the leaking connector.
After the second reassembly, the engine wouldn't idle and was making a loud sucking noise near the injectors. I suspected that the air jacket system had a leak. So the upper half of the intake came back off and I replaced all the old hose (just like an earlier post in this thread). The hoses didn't seem to have any cracks, but replacing it helped.
This time the engine ran fine and there weren't any water leaks, but now both fuel fittings on the fuel rail were dripping. Yay! I got to take the upper intake off one more time. To get the fuel fittings tight enough, I had to put a cheater bar on my flare wrench.
The third time was the charm: The engine ran, there were no major coolant leaks, and I wasn't about to burn my car up, but I did have to tighten the radiator hoses a bit.
I'm glad I did this project; I now have heat--a good thing now that we've got daytime temps in the 20s and 30s. I've got a lot more confidence working on the intake side of the engine, and that gnarly squid doesn't scare me anymore.
Lessons Learned- Don't forget to hook up the 12 V cable at the starter.
- Use lube on the O-rings, white lithium grease, silicone grease, whatever.
- Get the fuel lines good and tight.
- Get the hose clamps nice and tight too.
Cheers,
Martin