Somebody somewhere has written about it - use search.
You will lose some fluid, but not all of it - I think a gallon if I remember correctly from the article.
Doing a write-up would be appreciated by a lot of people.

Here are some threads...

https://www.crossfireforum.org/forum...tvt+thermostat

https://www.crossfireforum.org/forum...tvt+thermostat

Here it is... the last place I looked!!!

https://www.crossfireforum.org/forum...tvt+thermostat