changing coolant temp sensor?

[n240sx]

i have a really simple question for which i can't seem to find a definite answer. When replacing the coolant temp sensor, is it necessary to drain some of the coolant first? If so, should it be drained from just the radiator or the block? i have a pretty much stock 1991 240. thanks

[wootwoot]

I would just put a drain pan underneath to catch whatever falls out. No need to actually drain, I'm sure its prefered but whatevs.

[projectRDM]

If you're good you'll loose maybe 8ozs. Not enough to worry about.