Where is the thermostat at ?

Hello,

If you follow the upper radiator hose to the engine, you will find the thermostat housing. The thermostat is located inside that housing.
Remove two bolts to take the housing out and replace the thermostat.

Keep in mind to only work on the cooling system when the engine is cool.

https://www.2carpros.com/articles/how-an-engine-thermostat-works
https://www.2carpros.com/articles/replace-thermostat

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.