Is this easy to do yourself?
Are there any threads on a step by step basis on this?

Thanks

 

it's probably one of the easiest things to do yourself next to changing your spark plugs... follow the upper radiator hose back to the engine. You should see something that looks like someone blew a bubble and stuck a big straw into it that the host connects to. That's the housing that holds in the thermostat. it's usually two or three bolts that hold it on (10 or 12mm would be my guess on size) remove those bolts and lift the radiator hose up (it's going to leak some antifreeze so be prepared with a drip pan and rags) now you should be able to see the thermostat in there. pull that out. Clean all of your surfaces VERY well (sometimes removing the old gasket requires a scraper, if you use one be VERY carefull not to chip or "gouge" the metal surfaces) soak up any liquid you see inside the block side of the car with a rag. lower the upper radiator hose to drain it down into the drip pan. Dry all of your surfaces, get some High temp (be sure it's high temp) RTV gasket stuff and put a VERY thin layer on (put a bead on your finger and coat both sides) then place the new thermostat in and put on the gasket, put the bolts in a tighten it back down about as tight as you could get it with a scredriver. (aka hand tight) if you get it to tight it will squish out all your silicone (which is better than to loose). Remeber that if you're using a wrench or a socket that when you grab the end of it and twist it torques it harder than "hand tight" so don't over do it. Lit it seat for about 30-60 minutes if you can then start it up.
Now, on top of the "bubble" you should see a little thing that looks like a nut with a "nipple" on it (sorry can't describe it better) just before you start the car fill up your anti-freeze. Now after the car runs for about 5 minutes loosen up that little "nut" and leave it open until a bit of anti-freeze comes out (don't remove it all the way) once some anti-freeze comes out tighten it back down and then you've successfully "bled" your coolant system. let the car get up to temerature. Turn it off leave it sit till it cools down and fill your anti-freeze the rest of the way.

 

Sir nasty i beg to differ,, the t-stat IS NOT on the upper radiator hose ,, since 90, t-stat is located at the end of lower radiator hose..

there is a write up on how to replace t-stat on the DIY section ..