Testing powerhead temp sensor

[Mister Ed]

when trying to remove the powerhead temp sensor/switch for testing i discovered it is somehow stuck to the engine case. i removed the threaded cap that sits on the outside of the sensor well. tugging on the sensor lead gently did nothing. is there a clean way to free it up without damaging the unit?

i really want to verify its proper operation as it monitors a vital aspect of the engine.

50 hp Evinrude 89 model E50TLCE