I have been reading for years about the cheap a$$ thermostat housing. So be warned it's not a mater of IF but of WHEN. When was finally yesterday for me.
Here is the procedure for swap out
1) do this on a cool engine and not of the side of the road with a hot engine.
2) Need a new Thermostat (new ones are metal) and a 2" Screw Hose Clamp, and new rubber gasket
3) Remove the hoses, push the big hose down and out of the way to get to the smaller one
4) Use a 12 mm deep socket and remove both bolts holding on the housing
5) Replace with new parts
6) Throw away the spring clamp and use the new Hose Clamp. The plastic is just slightly bigger than the metal.
7) Add extra anti-freeze mix to replace what was spilled
Drive and Enjoy
Extra Bits O'Advice
If you can't get a new gasket, pull the gasket towards the top and push the housing into engine block pinching the gasket in place on the bottom. Screw in lightly the bottom bolt holding the gasket in place. Take a small wooden or plastic poker and start pushing the gasket back into the slot. Once the gasket pushes into the slot then tighten down the bolts.
If you are just doing casual maintenance (like changing and flushing the radiator fluid) go ahead and replace it. Don't do it while on the side of the road with a hot engine; you will burn your fingers.