Thermostat Replacement

I'm looking for information to replace a thermostat on a 99 Intrigue GLS
with a 3.5 ltr. V6 engine. Where to go or does some one have printed
material on this subject?

Hi
I have not done the job but will pass on what I can from the Olds manual. It looks to be located on the passenger side above the alternator. It is an integral unit with the "water inlet housing" which is a cast unit with (looks like) three water hoses attached.

1. Partially drain coolant
2.Remove clamp and disconnect radiator hose from water inlet housing.
3.Remove clamp and disconnect heater hose from water inlet housing.
4.Remove surge tank clamp and disconnect surge tank hose from WIH.
5.Remove water inlet housing bolts and remove housing.
6.Inspect and clean mating surfaces.
7.Replace inlet housing and thermostat as an assembly. (I don't know if that means you purchase them as an assembly, or that you simply install the thermostat into the housing on the bench and then put them into the car as an assembly)

1.Install water inlet housing and therostat assembly.
2.Install housing bolts with RTV sealer and tighten to 80 lb in.
3.Re-attach 3 hoses
4.Re-fill cooling system. (Be sure to use Dexcool coolant)
5.Inspect for leaks.

There you go! Hope it works.