Well, over Christmas break me and my 11 year old daughter (she is a tremendous help!) tackled changing the two thermostats. After I described it, and how it works, she was quick to pick it out on the Driver top side of the Cat. 6 bolts removed and a rubber hose clamp later, voila, easy to change and replace.
I did demonstrate to her on the stove how the old ones should work. One opened/closed reliably around 180 deg F, but the other one was a bit sketchy. Also took 2 gallons of antifreeze to replace what splashed out.
Next weekend, we purple power the radiator from the fan side and then gently hose it from the outside in, making sure we put in a temporary shower curtain to protect the Cat from the water and debris.
What have we forgotten?
300HP Cat Diesel