I just removed my thermostat...
If you are going to be replacing the hard lines: If you encounter
anything more than light resistance when turning the steel nuts that thread onto the aluminum thermostat, cut the nuts off to avoid damaging the aluminum thermo threads- they are soft and easily damaged. Thermostats are $$$$$
I buggered up the threads on one of mine (didn't see the tech write up until after I removed them). The repair kit our host offers probably works fine on the flexible line (engine) side of the thermo, but the two cast thread fittings that face down that attach the hard lines cannot really use the repair kit- it extends the length of the thermo threads out so much that when you attach your hard line to it, the hard line will be poking out below your floor almost an inch more than it should be.