M6 V10 engine t-stat replacement trick,,,,you don’t have to remove the intake manifolds completely,,,,just loosen them up and deattach the hoses from the front and both airmass sensor and lift them up and support them with something so they stay up.

The t-stat is under this metal cover,,,,just loosen the plastic wiring harness and just lift it up,,,,just like the intake manifold,,,,and you should have enough room to remove the t-stat

Here are pics of the t-stat and also there are 4 smaller o-ring seals which also should be replaced when replacing the t-stat.