What to disassemble to change thermostat

You will need to remove your air cleaner and duct assembly. You will then see the thermostat housing sandwiched between the back of the intake manifold and the exhaust crossover pipe. The service manual says to remove the exhaust crossover pipe, but trust me, you do not want to attempt this unless you have access to a torch to heat the nuts that hold the thing to the exhaust manifolds. If you break a stud, then you are going to be removing an exhaust manifold for broken stud removal. If you take the 8mm screws out of the heat shield on the exhaust crossover pipe, you can wiggle the heat shield out. This will provide enough room to get the lower thermostat housing bolt out. It is a pain to do it this way, but it works and will prevent broken exhaust pipe studs. Sometimes the little 8mm bolts will also break, but since they only hold the heat shield, it is of no great consequence.

Then all you have to do is remove the two bolts that hold the thermostat housing to the manifold. The thermostat is directly under it.
Then the only other real "trick" is getting the thermostat and O-ring to stay in the correct position while you put the thermostat bolts back in. A trick that I use is a small wooden wedge. I put the thermostat housing into place over the thermostat and O-ring, then place mt wedge between the thermostat housing and the crossover pipe to hold the thermostat housing in place while I start the bolts. Otherwise, the thermostat tends to slide out the bottom while you are trying to get the bolts started.

Let me know how it goes...