91 Camry water bypass pipe removal question

[mgta]

I have a 1991, 2.0L, 3S-FE Camry. I have to replace the radiator and it's leaking antifreeze from where the water bypass pipes bolt in to the thermostat housing.

According to a diagram I got from the dealer, 2 10mm nuts hold it to the housing, and then there are 2 other bolts(12mm) holding it. I undid the 2 10mm nuts and the 12mm bolt right before one of the pipes connects to a hose and the other pipe bends and goes to god knows where. I tried prying the pipes loose at the housing, but then got the feeling that I was about to break something that I really didn't want broken so I stopped. Is this other bolt what's keeping it in place? Where is it? I couldn't find it.

Also, the repair manual at the library said that there's an o-ring and a gasket for the pipes. The dealer said that there's an o-ring but no gasket and that they use silicone instead. Does it matter?

[ProMan]

If you face the engine from front of car, the bypass pipe bend 90 degrees toward the rear of the car. There lies a bolt secure the pipe to the side of the cylinder head. Just follow the pipe closely after the bend, you will see it.