Changing Wires

Okay how hard is it to change the wiring lead to the temp sensor on the side of the engine....I am having problems (see previous thread) and read that maybe my leads were bad...is this major work?

are we talk replacing the entire wire? its not the wire that goes bad, its the connector that goes bad. all you do is cut the 2 wires and splice the new connector in. but cut at least 1-2" off past the connector so in case corrosion got up into the wires.